Authors: Chang Liu, Yifan Wang, Mario Romero-Ortega, Argyrios Stampas, Yingchun Zhang, Philippe Zimmern, Zhengwei Li
Categories: Article, bioelectronic medicine, bladder monitoring, lower urinary tract dysfunction (LUTD), neurogenic bladder, neuromodulation, urotechnology
Source: Advanced healthcare materials
Authors: Chang Liu, Yifan Wang, Mario Romero-Ortega, Argyrios Stampas, Yingchun Zhang, Philippe Zimmern, Zhengwei Li
Neurogenic bladder and lower urinary tract (LUT) dysfunctions encompass a wide variety of urinary disorders resulting from nervous system impairments. Unfortunately, conventional treatments are still limited and can have significant complication rates, especially when stent implantations or other surgical procedures are involved. Therefore, there is a critical need to develop novel therapeutic strategies and pharmacological approaches to address these challenging urological conditions. Recent technological advances offer promising solutions to overcome some of these challenges faced by patients with bladder and LUT dysfunction. This review summarizes recent progress in advanced urotechnologies, focusing on bladder monitoring and neuromodulation approaches, advanced medical instruments and devices, and the latest wireless, battery-free bioelectronic implants for bladder care. These emerging engineered platforms offer the potential for real-time monitoring and improved patient outcomes while minimizing the risks associated with traditional treatments. Outlook and future directions are also discussed, highlighting how technological innovations—enabled by interdisciplinary efforts—can lead to next-generation urotechnologies. These include multimodal closed-loop strategies, artificial intelligence, deep-tissue sensing techniques, and other approaches aimed at addressing a wide variety of complex urological conditions affecting the bladder and beyond.
The urinary bladder is a hollow, distensible organ in the pelvic area that serves as a reservoir to store and release urine.^[1]^ The unique muscular structure of the bladder wall enables expansion at low pressure without compromising compliance, while contraction requires complex neuronal signaling controlled by the brain and depends on bladder volume.^[2]^ Innervation from both sympathetic and parasympathetic fibers via the pelvic plexus controls detrusor muscle activity and sphincter coordination, enabling voluntary continence and effective emptying.^[3]^ Disruptions in this neuromuscular control give rise to a spectrum of non-malignant bladder dysfunctions, including overactive bladder (OAB), underactive bladder (UAB), urinary incontinence (UI), and neurogenic bladder (NB), commonly associated with neurological disorders such as spinal cord injury (SCI), multiple sclerosis, Parkinson’s disease, and stroke.^[4]^ The pathophysiology of these conditions varies but frequently involves detrusor overactivity (DO) or underactivity (DU), detrusor-sphincter dyssynergia (DSD), and abnormal sensory or motor pathways, manifesting clinically as urgency, frequency, urinary retention, or involuntary leakage.^[5]^
Conventional clinical treatments for neurogenic bladder include behavioral therapies,^[6]^ medications,^[7]^ intradetrusor injections (e.g., botulinum toxin),^[8]^ intermittent catheterization,^[9]^ and various invasive surgeries (e.g., augmentation cystoplasty and urinary diversions).^[10]^ While these approaches offer therapeutic benefits, they are often associated with unfavorable side effects, such as low efficacy, urinary tract infection (UTI), irritation, discomfort, and even bladder or renal damage.^[11–13]^ In addition, neuromodulation has become a valid therapeutic option for patients with various bladder and LUT conditions.^[14]^ However, conventional neuromodulation technologies rely largely on electrical stimulation, which can cause discomfort, pain, inflammation or even nerve injury.^[15,16]^ Therefore, there is a critical need to develop novel and advanced urological technologies for both monitoring and treatment of these dysfunctions. Current evaluation methods, such as urodynamic studies (UDS), provide only brief, clinic-based assessments and fail to reflect the continuous, real-world dynamics of bladder function.^[17]^ This is especially limiting in neurogenic bladder, where sensory input and neural control are disrupted. Real-time bladder monitoring technologies offer individualized, dynamic assessments of detrusor activity and voiding patterns, enabling more accurate diagnosis and symptom correlation. Neuromodulation complements this by targeting aberrant signaling in neural pathways to restore functional control, particularly in cases unresponsive to standard treatments. Together, these strategies enable closed-loop therapeutic systems that emulate physiological feedback, allowing for responsive, personalized interventions that address both diagnosis and treatment limitations in current care.
Advanced bladder monitoring and neuromodulation strategies are shifting from bulky devices requiring regular visits to medical facilities to miniaturized wireless devices suitable for home use, as illustrated by the timeline in Figure 1. Emerging bladder monitoring devices,^[18–25]^ such as wearable ultrasound patches^[18]^ and implantable bioelectronic systems,^[19]^ are expected to facilitate early diagnosis and allow tracking of disease progression, potentially replacing traditional follow-up hospital visits after surgery. By integrating smart functional biomaterials, newly developed bioelectronic implantable devices have enabled continuous multimodal monitoring of bladder activity.^[20]^ Regarding neuromodulation,^[26–33]^ recently Food and Drug Administration (FDA)-approved sacral and tibial neuromodulators with compact designs provide patients with greater flexibility for optimal outcomes. In addition, technological advances in wireless bioelectronics offer promising solutions to overcome some of the challenges faced by patients with urological dysfunction. More intriguingly, these systems^[26,30]^ support autonomous closed-loop operation and neuromodulation, incorporate artificial intelligence (AI) as well as edge computing technologies, and significantly enhance their diagnostic and therapeutic performance-representing a clear trend in the development of cutting-edge urotechnology. A comprehensive summary of emerging urological devices is presented in Table 1.
For example, recent advances in flexible and stretchable electronics have yielded numerous implantable platforms capable of intimately interfacing with the internal organs.^[34–42]^ Innovative mechanical designs allow electronic devices to integrate with soft tissues in a dynamic, conformal fashion, which is particularly useful for urological applications given the bladder’s significant volumetric change (up to 400% expansion).^[26]^ In recent years, various flexible bioelectrodes have been developed with a broad range of functionalities to improve the patients’ quality of life.^[43]^ Bioelectronic systems integrated with advanced biosensors (for example, strain gauges, pressure sensors, electromyography (EMG) sensors, etc.) have achieved not only real-time, continuous bladder volume and pressure monitoring but also the closed-loop neuromodulation to manage neurogenic bladder disorders.
This review focuses exclusively on non-malignant bladder conditions which are characterized by functional disruptions in neural or myogenic control of bladder activity. In contrast to malignant diseases such as bladder cancer which require oncological interventions like surgery, chemotherapy, or immunotherapy, non-malignant bladder dysfunctions often arise from neurogenic or idiopathic origins. These conditions are frequently chronic, poorly responsive to conventional treatments, and pose a substantial burden on quality of life. Consequently, they present a critical opportunity for innovation in neuromodulation and sensor-based therapeutic strategies, which are the central focus of this review. While several recent reviews have explored bladder monitoring technologies^[44,45]^ or neuromodulation approaches^[14,16]^ independently, few have provided a comprehensive and integrated perspective that links these rapidly advancing domains. This review addresses that gap by synthesizing recent developments in both areas, with a particular focus on emerging soft, wireless, and battery-free bioelectronic systems designed for real-time, closed-loop bladder management. By connecting physiological principles, device engineering strategies, and translational challenges, this review offers a multidisciplinary view intended to support future development and clinical implementation of next-generation urotechnologies.
This review begins with a brief overview of the emerging bioelectronics-based approaches for multifaceted urinary bladder management and their urological applications in volume monitoring (e.g., ultrasound and strain gauge),^[44]^ pressure monitoring,^[25]^ EMG sensing,^[20]^ and various neuromodulation technologies (e.g., sacral and tibial nerve stimulation),^[46,47]^ direct electrical stimulation,^[26]^ and wireless closed-loop optogenetic neuromodulation,^[30,48]^ as summarized in Figure 2. To structure the discussion, we organize the review based on device integration level rather than by function alone. Section 2 introduces foundational technological concepts for bladder sensing and stimulation. Section 3 focuses on standalone biomedical devices currently in use or development for monitoring or neuromodulation. Section 4 highlights fully integrated bioelectronic systems that combine these functions into wireless, closed-loop platforms. This progression reflects the translational evolution from conventional tools to advanced, multifunctional systems. Finally, we discuss future directions for next-generation urological technologies, including sophisticated devices, multimodal closed-loop neuromodulation, and artificial intelligence.
This section introduces the physiological mechanisms and engineering strategies that underpin both established and emerging technologies for bladder monitoring and neuromodulation. We begin with sensing modalities for bladder volume (e.g., ultrasound, NIRS, electrical impedance) and pressure (e.g., intravesical, suburothelial sensors), followed by neuromodulation methods targeting the pudendal, sacral, and tibial nerves. These foundational concepts support the technologies discussed in later sections.
There are numerous bladder monitoring approaches, including invasive and noninvasive techniques, to manage various urological conditions. In clinical settings, conventional invasive monitoring methods such as urinary catheterization,^[49]^ cystoscopy,^[50]^ and urodynamics^[44]^ are still widely used to evaluate bladder volume and pressure. However, these procedures can lead to discomfort, pain, bladder perforation, and the risk of urinary tract infections, prompting many patients to choose minimally invasive or noninvasive alternatives. These options include ultrasound imaging,^[51,52]^ near-infrared spectroscopy (NIRS),^[53,54]^ electrical impedance sensing,^[55,56]^ sensor implantations,^[57,58]^ and others.
Ultrasound technology offers valuable insights into LUT dysfunction using high-frequency sound waves.^[59]^ It is a noninvasive, safe, and painless method that involves placing a transmitter and receiver on the skin above the bladder to assess bladder dimensions and volume (Figure 3A i).^[60]^ The use of ultrasound for bladder volume monitoring dates back to the 20th century, when a miniaturized ultrasonic scanner for bladder volume was first developed.^[51]^ Technological progress has since significantly improved and refined such ultrasound devices. Typically, the modern scanner system employed low-profile ultrasound transducers to capture reflected signals from both the anterior and posterior bladder walls, subsequently deducing the bladder’s shape and determining its volume.^[52]^ A modern example is a conformable ultrasound bladder patch (cUSB-Patch) positioned on the lower abdomen, based on multiple phased-array transducers embedded in a stretchable substrate. This device provides mechanically robust and real-time in vivo bladder volume monitoring (Figure 4A).^[18]^
Near-infrared spectroscopy (NIRS) is another noninvasive, cost-effective technique for monitoring bladder volume in real-time by measuring changes in oxygenated and deoxygenated hemoglobin concentrations during the bladder filling and voiding.^[61]^ A typical NIRS system consists of LED light sources and photodetectors that emit and detect light, as well as a photodetector that measures the absorption of the emitted light. The setup is typically placed on the skin between the midline of the lower abdomen and the symphysis pubis (Figure 3A ii).^[53]^ Traditionally, NIRS has been used to monitor and diagnose conditions related to the brain and skeletal muscles. However, its application in urology is gaining interest, with studies exploring its potential in conditions such as bladder outlet obstruction,^[62]^ overactive bladder,^[63,64]^ underactive bladder,^[53]^ and neurogenic lower urinary tract disease.^[65]^ Studies indicate that bladder volume measurements obtained with a NIRS system are as accurate as those from ultrasound.^[66]^ By using NIRS, patients with conditions like incontinence or urinary retention can be alerted to bladder filling, potentially preventing accidents and protecting renal function.
Another bladder monitoring technology under development is electrical impedance. This noninvasive, low-cost method measures the resistance to the flow of a small electrical current through biological tissue.^[67]^ To monitor bladder volume, electrodes placed on the abdominal skin or bladder surface apply a current and track changes in bladder impedance during filling and emptying. Based on measurement technique, electrical impedances monitoring can be categorized into bioelectrical impedance analysis (BIA) and electrical impedance tomography (EIT). Human observation studies have shown a correlation between electrical impedance and bladder volume, but impedance monitoring has not yet reached clinical application (see Table 1).^[55]^ It remains an active area of research and development with the potential integration into wearable systems for continuous, real-time bladder monitoring.^[67]^
Besides bladder volume, monitoring bladder pressure is also important for preventing and predicting bladder dysfunction.^[68,69]^ Bladder implantable pressure sensors generally fall into two types based on the intraluminal (within the bladder lumen) and suburothelial (within the bladder wall). In intraluminal sensors, the pressure sensing unit is encapsulated, allowing it to float or anchor inside the bladder and protecting it from the harsh urine environment. For example, a minimally invasive pressure monitoring system has been developed, which consists of a small pressure sensor, a radio frequency (RF) communication module and a control ASIC chip, all sealed inside a balloon that floats in the bladder (Figure 3A iii).^[57]^ The system can continuously monitor intravesical pressure over a wide range and has been used to study bladder malfunction in preclinical models.
The urothelium, the compliant lining of the inner bladder wall, is believed to be robust enough to encapsulate small sensor devices. Implanting device sensors in the bladder wall have been proposed as a means to shield the sensing units from direct urine exposure. This approach aims to prevent mineral encrustation and the formation of stones, which could impair the device’s functionality. For instance, a pressure sensor coated in silicone rubber and implanted in the suburothelial space can measure bladder pressure, showing a positive correlation with intravesical pressure (Figure 3A iv).^[58]^ Animal studies (in female calves) have demonstrated the feasibility of this approach, but also revealed limitations such as risk of device erosion into the bladder lumen. This finding underscores the need for devices designed for chronic intravesical pressure monitoring that avoid such complications. Developing novel encapsulation materials that resist encrustation and stone formation (from constant urine exposure) is an active area of research to improve long-term intravesical pressure sensors.
To underscore the need for advanced diagnostic technologies, we summarize current surveillance strategies for neurogenic lower urinary tract dysfunction (NLUTD) based on AUA/SUFU and EAU guidelines. These include tools such as bladder ultrasound, uroflowmetry, post-void residual measurement, and urodynamics, which are routinely used in clinical practice. However, as outlined in Table 2, each of these modalities has significant limitations in terms of invasiveness, temporal resolution, reliance on patient compliance, or ability to provide dynamic or continuous functional data. This highlights a critical gap in current care pathways that emerging sensing and monitoring technologies aim to address.
To further frame the translational relevance of emerging neuromodulation strategies, we summarize standard-of-care therapeutic interventions for NLUTD, including behavioral therapies, pharmacologic treatments and catheterization approaches. Table 3 outlines these treatments, their mechanisms of action, and key limitations. While these therapies remain central to clinical management, they often present significant drawbacks—such as limited efficacy, systemic side effects, procedural invasiveness, or poor long-term adherence—especially in patients with complex or refractory bladder dysfunction.^[70,71]^ These limitations underscore the need for next-generation therapeutic modalities that offer greater precision, adaptability, and patient-centered delivery.
Neuromodulation refers to the therapeutic strategy of modifying nerve activity through targeted stimulation to restore normal function or disrupt abnormal signaling pathways, ultimately improving the patient’s quality of life.^[72,73]^ This technique can alleviate LUT symptoms associated with various conditions such as interstitial cystitis, urinary incontinence, neurogenic detrusor overactivity, DSD and others. Although the exact mechanism by which neuromodulation affects the lower urinary tract are not fully understood, neuromodulation techniques are typically categorized based on the target nerve. These include the stimulation of pudendal nerve (Figure 3B i),^[74–77]^ sacral nerve (Figure 3B ii),^[77–79]^ and tibial nerve (Figure 3B iii,iv).^[47,80]^ Each of these targets corresponds to established neuromodulation therapies (e.g., sacral neuromodulation and tibial nerve stimulation), which modulate reflex pathways to influence bladder storage and voiding function.
Pudendal neuromodulation (PNM) involves direct stimulation of the pudendal nerve, which innervates the external urethral sphincter and perineal area, to modulate bladder function and inhibit overactivity. PNM may offer superior effectiveness compared to sacral neurostimulation (SNM) by directly targeting the pudendal afferent nerves, which play a key role in inhibiting the voiding reflex. This makes PNM a promising alternative treatment option in recent decades. While studies suggest that PNM is safe and effective for treating LUT dysfunctions, the evidence remains limited due to small sample sizes, rendering meta-analysis unfeasible. Further research is needed to establish its role in treatment algorithms, and currently no regulatory agency, including FDA, has approved PNM devices for LUT dysfunction treatment.^[74]^ Additionally, sacral neurostimulation (SNM) is a minimally invasive procedure used to manage various bladder disorders including OAB, urgency urinary incontinence (UUI), and non-obstructive urinary retention.^[76]^ FDA-approved SNM devices, such as Medtronic InterStim and Axonics, are illustrated in Figure 1, highlighting their latest advancements. Moreover, percutaneous tibial nerve stimulation (PTNS) (Figure 3B iii)^[80–82]^ has received FDA approval as a clinical therapy for OAB.^[83]^ However, the invasive method and long maintenance sessions often reduce patient compliance. As an alternative, noninvasive transcutaneous tibial nerve stimulation (TTNS) has developed as a popular alternative (Figure 3B iv).^[47,84,85]^ TTNS can be applied conveniently at home, offering a shorter preparation time and less discomfort.^[86]^
In addition, a bladder electrical stimulation system has been developed, with implants placed in the bladder wall. This wireless, closed-loop electronic system represents an innovative technology designed to analyze and regulate bladder function. Typically, the system comprises a wireless module to connect the electronic components and external devices (Figure 3B v).^[26]^ The electronic components consist of strain gauge, EMG electrodes and multiple electronic stimulation electrodes which can enable electronic neuromodulation and monitoring of bladder activities. Although animal experiments have been conducted, long-term evaluations are still required, and therefore, the system is not yet ready for clinical use (refer to Table 1 for details).
Beyond electrical nerve stimulation, optogenetics stands as a relatively new noninvasive neuromodulation technology which allows for the manipulation and monitoring of biological processes using light-sensitive proteins and electronic components.^[87–89]^ One example is using optogenetics directly to stimulate urothelial cells to induce bladder contractions. The study combines a uroplakin II (UPK2) Cre mouse with a mouse engineered to express the light-activated cation channel, channelrhodopsin-2 (ChR2), upon cre expression.^[90]^ Optogenetic stimulation of urothelial cells in UPK2-ChR2 mice leads to cell depolarization and ATP releasing. Meanwhile, increased bladder pressure and pelvic nerve activity is noticed by cystometry recordings. As a consequence, this approach demonstrates that using optogenetic method on urothelial cells can induce bladder contraction which shed a light on the study of urothelial-to-sensory neuron communication and LUT pathophysiology (Figure 3B vi).^[90]^
This section reviews biomedical devices currently used in clinical practice or in late-stage development. These include systems for either monitoring (e.g., wearable bladder scanners, pressure sensors) or neuromodulation (e.g., SNS, PTNS), but not both. Devices in this category reflect the clinical standard or near-term options for addressing specific bladder dysfunction. Recent efforts to integrate smart, multifunctional materials, such as stretchable electronics or soft biointerfaces, are also beginning to enhance device performance and user comfort in select systems.
Volume and pressure present as two of the most critical physiological parameters of bladder functionality. Numerous bladder monitoring systems have been developed to measure them, with further details summarized in Table 1. Below, we describe several notable examples of advanced bladder monitoring devices.
The conformable ultrasound bladder patch (cUSB-Patch) introduced earlier is a prime example of an advanced bladder monitoring device. It is a conformable ultrasound bladder patch that adheres to the lower abdomen and continuously captures bladder images (Figure 4A i–iii), using phased-array transducers in a stretchable polymer matrix. The cUSB-Patch provides real-time bladder volume monitoring with accuracy on par with standard ultrasound and can adapt to various body shapes and bladder positions (Figure 4A iv–vi).^[18]^ It consists of five 1D phased arrays (each with a piezoelectric element, backing layer, and matching layers) and demonstrated bladder volume assessment comparable to standard clinical ultrasound (Figure 4A vii–x). Its versatility allows it to detect bladder changes at different depths, and clinical testing showed it could effectively monitor bladder volume without the need for a trained sonographer. This device has completed clinical trials, demonstrating the feasibility of ultrasound-based bladder monitoring in a wearable format.
An alternative technology for measuring bladder volume is electrical bioimpedance. A wearable bioimpedance system has been prototyped that consists of sensor electronics, batteries and skin to monitor bladder volume (Figure 4B).^[55]^ This portable system monitors changes in abdominal electrical impedance during bladder filling and voiding, using an algorithm to estimate bladder volume. The approach offers a non-imaging, continuous monitoring method for bladder fullness. Currently, this bioimpedance system is in the human observational study phase, and further validation will determine its accuracy and reliability as an alternative to ultrasound or catheter-based measurements.
Near-infrared spectroscopy has been applied in a compact, wearable bladder monitor. Figure 4C shows a small, cost-effective NIRS that continuously monitor bladder status.^[91]^ The system consists of a NIRS device, LED lights and detectors (Figure 4C i,ii). The device utilizes 950 nm wavelength LED light, closely aligned with the absorption peak of water at 975 nm, which is the primary compound in urine (constituting ≈95%).^[92]^ This device effectively distinguishes between full and empty bladder and provides real-time data. In practice, such a tool could alert patients or caregivers when the bladder needs emptying, thereby preventing accidents and protecting the upper urinary tract. Early studies show that patients with conditions like UI or urinary retention can use this NIRS device to accurately gauge bladder volume and time voids appropriately.
Bladder pressure is often measured via gold standard of catheter-based urodynamics,^[20]^ but that method is invasive and provides only snapshots of bladder function.^[93]^ To address this issue, a fully wireless intravesical pressure sensor called the Uromonitor has been developed as a CE-marked commercial product.^[21]^ The Uromonitor is a small device inserted into the bladder which comprises a pressure sensor, flexible electronics, and a lithium battery sealed in silicone (Figure 4D). In clinical evaluation, the UroMonitor allowed catheter-free bladder pressure monitoring. The study reveals that the patients reported low pain score (0 to 2 on a 10 scale) with the device, and there are no instances of infection or altered voiding behavior during use. Importantly, the results demonstrate that the Uromonitor successfully detected 98% of both voiding and nonvoiding bladder contractions recorded by conventional urodynamics with minimal post-void residual urine. This demonstrates that a wireless intravesical sensor can accurately capture bladder pressure dynamics while greatly reducing patient discomfort and infection risk.
One study presents an innovative implantable bladder interface that integrates highly stretchable carbon nanotube (CNT) strain sensors with platinum-silicone composite electrodes to enable real-time bladder fullness detection and electrically induced contractions.^[24]^ Designed on an Ecoflex 00–50 silicone substrate, the device is biocompatible, ultra-compliant, and mechanically stable, making it ideal for implantation on the dynamic bladder surface. Figure 4E-i illustrates the fabrication process of the resistive-type sensing device, which features a single-layer CNT percolation network for strain detection and an integrated electrode array for stimulation. The fabrication process includes spray deposition of CNTs, patterning of Ti/Pt/Au bonding pads, encapsulation with Ecoflex, and the integration of a durable medical-grade superalloy wire connection, ensuring long-term stability under physiological conditions. Figure 4E-ii depicts an in vivo setup, where the resistive device is sutured onto the bladder wall of a feline model. The device is secured using six 1 mm × 1 mm PTFE pledgets, which reinforce the sutures and prevent substrate tearing, maintaining secure and stable attachment. This setup enables accurate measurement of bladder wall strain while providing a reliable electrical interface for stimulation. The study demonstrates that the sensor effectively correlates resistance changes with bladder volume, and electrical stimulation successfully induces bladder contractions, supporting its potential clinical application for neurogenic bladder management and SCI rehabilitation.
A recent study introduces an advanced integrated bladder voiding system that combines a flexible capacitive sensor with a shape memory alloy (SMA)-based actuator, creating a closed-loop bladder management system for individuals with neurogenic underactive bladder (UAB).^[23]^ This system addresses bladder dysfunction, particularly in cases where sensory feedback and muscle control are impaired, such as following a SCI. This system includes a capacitive interdigitated sensor mounted on a polyimide (PI) substrate and paired with an SMA-based actuator on a polyvinyl chloride (PVC) substrate. The bladder’s volume changes are detected by the sensor through capacitance variations, while the actuator applies compression via a NiTi SMA spring to facilitate bladder emptying. Figure 4F-i highlights the system’s efficiency during the compression phase, demonstrating that the actuator successfully voids up to 74.23% of bladder volume in an anesthetized rat model. The capacitance response of the sensor shows an initial sharp increase upon voltage application, followed by a gradual decline as the bladder empties, ensuring precise real-time control and preventing urinary retention and overfilling complications (Figure 4 ii). This study introduces a novel bladder assistive technology, offering a minimally invasive, soft robotic solution with high voiding efficiency (71%–100%), adaptable for real-time sensing and actuation in various organ systems, and demonstrating strong clinical potential for bladder dysfunction management.
Smart hydrogel biomaterials offer another promising avenue for bladder monitoring, as they can be engineered to have tissue-like softness and tunable mechanical and conductive properties, allowing them to adhere and conform to organ surfaces while withstanding repetitive stretching for long-term functionality.^[94–96]^ A recently developed intrinsically non-swellable hydrogel with dynamic nanoconfinement networks has been used for bladder volume monitoring. This hydrogel is robust, self-healing, conductive, and even 3D-printable.^[97]^ In an ex vivo experiment, a strip of this hydrogel was attached to a porcine bladder model and its electrical resistance was measured while varying bladder volume by adding or removing fluid. The linear correlation between the relative resistance of the hydrogel and bladder liquid volume serves as a reliable tool for bladder volume monitoring (Figure 4G i).^[97]^ A control system was able to inject or drain fluid to simulate bladder filling and voiding (Figure 4G (ii)), and the hydrogel sensor reliably tracked these volume changes. The hydrogel can seamlessly adapt to the bladder, indicating its dependable ability to sense bladder strain and monitor bladder volume. Its biocompatibility and degradability could mean it causes minimal inflammatory response and might eventually dissolve, avoiding the need for removal surgery.
Flexible materials can be integrated with electronics to enable bladder pressure monitoring.^[22,98]^ A noninvasive urinary bladder pressure wireless measurement system is fabricated by employing a biomimetic structured piezoresistive sensor and low-power Bluetooth technology.^[22]^ The sandwich-structured sensor is composed of PDMS-MWCNT electrodes and a gold-coated polyethylene terephthalate (PET) layer (Figure 4H i), reaching a sensitivity of 0.19 kPa^−1^ in the range of 0–3 kPa. When pressure is applied to the sensor, its resistance decreases due to an increase in the contact area and the number of connections between the carbon nanotubes. Figure 4H ii presents real-time pressure change curves in response to a slight touch on the pig bladder. This sensor shows an effective method for assisting clinicians and patients in diagnosing abdominal impairments in real-time. This sensor provides an effective method for aiding clinicians and patients in the real-time diagnosis of abdominal impairments. While many of these soft and flexible sensor technologies are still at the bench research or animal experimentation phase (see Table 1 for details), they represent important steps toward unobtrusive, continuous bladder monitoring in everyday life.
Bladder monitoring plays a crucial role in assessing bladder function, particularly for patients with bladder dysfunction. Bladder volume and pressure usually are the two crucial parameters, as abnormalities in either can lead to pathological conditions. While the urodynamic test remains the gold standard, it is associated with several complications including urinary tract infection, dysuria, hematuria, and urinary retention.^[99]^ Advances in technology have led to the development of less invasive and more convenient bladder monitoring devices, reducing complications and improving accessibility. Noninvasive-techniques such as ultrasonography, near-infrared spectroscopy (NIRS), and bioimpedance are widely explored for bladder volume monitoring. Ultrasonography, despite being effective, requires manual expertise and suffers from size and portability limitations. NIRS, while noninvasive, faces challenges such as motion artifacts and data reproducibility issues, and the large, heavy nature of NIRS devices restricts their portability. Bioimpedance, though less studied, remains promising due to its low cost and convenience. In addition to volume monitoring, pressure monitoring is also crucial for the bladder health. However, current methods often require invasive surgery and primarily focus on intravesical measurement, making them less practical for widespread clinical use. Furthermore, patient movement and abdominal pressure fluctuations may cause artifacts.
Advancements in bioelectronics, biomaterials and neuroengineering, have also driven progress in implantable neuromodulation devices for bladder control. These innovations aim to address bladder dysfunction with minimal patient burden. One area of development is in improved electrode technologies for stimulating nerves or bladder tissues. Various bipolar electrodes have been fabricated to directly stimulate the bladder wall.^[100,101]^ For example, researchers have explored surface electrodes versus penetrating coil electrodes (Permaloc) to determine effective stimulation methods. Stimulation failed to provoke voiding in this model, possibly due to suboptimal stimulation parameters, electrode placement, or limitations of the animal model. Further research is needed to modify such electrodes or stimulation protocols to achieve bladder contractions sufficient for voiding or to reduce outlet resistance during stimulation-induced void attempts.
Intravesical electrical stimulation (IVES) has been investigated as another approach, particularly for underactive bladder or detrusor underactivity (DU). IVES involves electrical stimulation delivered inside the bladder (for example, via a catheter electrode) to improve bladder emptying. In a clinical trial by Liao and colleagues, 105 patients with DU received IVES treatment.^[31]^ The results show that 76.4% of the patients experienced improved voiding efficiency, and post-void residual urine volumes are significantly reduced after IVES (Figure 4I). This suggests IVES can enhance bladder sensation and emptying in patients with severely impaired detrusor contractility.
With fewer side effects, reduced discomfort, and improved quality of life, neuromodulation has become prevalent therapy for various urological problems.^[102]^ A wide spectrum of electrical nerve stimulation devices exists, differing in stimulation site and invasiveness. These range from fully implantable systems (like sacral nerve stimulators or implanted tibial nerve stimulators) to minimally invasive or noninvasive methods (such as percutaneous tibial nerve stimulation, PTNS, and transcutaneous tibial nerve stimulation, TTNS).
Inspired by the spinal neural networks involved in LUT regulation, a transcutaneous spinal cord neuromodulator (SCONE) has been developed to treat OAB (Figure 4J) and has received breakthrough device designation from the FDA.^[27,103]^ By positioning electrodes over T11–L2 and S2–S4, SCONE delivers electrical signals to spinal segments that correspond to the sympathetic chain and sacral nuclei involved in bladder control.^[27]^ This noninvasive, home-based system avoids the complications associated with implanted devices and allows self-administered therapy with minimal discomfort. In a pilot clinical trial, 12 weeks of SCONE therapy results in a reduction in urge urinary incontinence episodes, with no reported adverse effects.
Sacral nerve stimulation (SNS) was developed in the 1970s and, after several technical improvements, gained FDA approval for treating urge urinary incontinence.^[104]^ One of the leading modern SNS systems is the Axonics system.^[105]^ The Axonics implantable pulse generator (IPG) measures only 45 × 23 × 6 mm^3^ and features an innovative titanium-ceramic construction (Figure 4K). It is capable of automatically adjusting voltage, ensuring continuous and stable stimulation of the nerve. The one- and two-year outcome studies on the Axonics system for treating urinary urgency incontinence (UUI) demonstrate that the majority of participants experienced statistically significant clinical improvements in UUI symptoms.^[106,107]^ Another long-term study (spanning over 20 years of experience) found that more than 60% of patients benefited from sacral neuromodulation stimulation in both mid- and long-term follow-up periods, with a significant improvement in their quality of life.^[108]^ Additionally, recent research suggests SNS may modulate central nervous system for example, OAB patients showed abnormal deactivation of the prefrontal cortex that was reversed after successful SNS treatment.^[109]^
Another common location for neuromodulation is the pelvic nerve. The pelvic nerve represents a promising target of stimulation to regulate bladder function. It offers autonomic efferent inputs capable of contracting the bladder detrusor muscle, rendering it well-suited for bladder neuromodulation. Flexible neural clips (FNC) are developed to control bladder function while monitoring bladder pressure, as shown in Figure 4L.^[32]^ Unlike traditional cuff electrodes that may apply excessive pressure or lack stability, FNC NCs provide a minimally invasive, conformal interface tailored for delicate peripheral nerves. They are constructed with a polyimide-Au-polyimide sandwiched structure, which allows them to easily and reliably interface with the pelvic nerve due to their lightweight, flexible, and open-loop clip design. This enables chronic, stable nerve contact without compromising nerve function. Throughout the experiment, as the stimulation currents gradually increase within the range of 25–200 μA, bladder contractions leading to a positive rise in bladder pressure are observed, ultimately resulting in micturition.^[110]^ These findings demonstrate the successful attainment of functional neuromodulation.
Another promising strategy is pudendal neuromodulation, particularly in the context of SCI. A novel implantable pudendal stimulator developed by Tai and colleagues features three output channels designed to target different aspects of pudendal nerve activity.^[28]^ Channel 1 is linked to the bipolar cuff electrode, generating a biphasic pulse with a frequency range of 1–100 Hz, an intensity between 0.05–10 mA, and a pulse width of 0.03–1 ms. Channels 2 and 3 are associated with tripolar cuff electrodes, delivering a continuous biphasic square waveform with a high-frequency range of 1–30 kHz and intensity varying from 0.1–15 mA (Figure 4M). The stimulator is implanted in complete spinal cord injury (SCI) cats and tests weekly under awake conditions. By simultaneously stimulating the pudendal nerves at different frequencies, their results show that the recovery of bladder storage and voiding function after SCI could be achieved.
Peroneal nerve stimulation also presents a valuable option for neuromodulation. A newly developed neuromodulation system integrates an impulse generator, multilayer active electrodes, and a biofeedback foot sensor to selectively stimulate individual nerve branches.^[29]^ This system incorporates real-time feedback and targeted stimulation, significantly improving therapeutic precision. Unlike more invasive implantable devices such as sacral or tibial nerve stimulators, this peroneal system is wearable, noninvasive, and potentially more cost-effective. While long-term efficacy data are still emerging, early results suggest this method may match or surpass conventional overactive bladder (OAB) treatments in symptom relief, while offering better patient comfort and compliance. In contrast, the 2023 follow-up study represents a significant advancement in clinical validation, employing a prospective, randomized, multicenter trial design with a head-to-head comparison against solifenacin, a standard pharmacological treatment.^[111]^ The updated trial confirms not only the therapeutic efficacy of peroneal electrical transcutaneous neuromodulation (eTNM) (Figure 4N i) using URIS neuromodulation (Figure 4N ii) but also reveals superior safety and tolerability, with a fourfold reduction in treatment-related adverse events (12% vs. 48%) and improved patient satisfaction. Together, these findings establish high-level clinical evidence supporting peroneal eTNM as a safe, effective, and accessible noninvasive alternative to pharmacotherapy for managing overactive bladder.
Among the most recent FDA-approved neuromodulation options is implantable tibial nerve stimulation (iTNS), developed for managing urgency urinary incontinence (UUI). iTNS offers distinct advantages over PTNS and TTNS by providing a fully implantable, minimally invasive solution. Figure 4O i showcases an iTNS device from BlueWind Medical, which features a miniature implant measuring 3 cm in length and 3 mm in diameter.^[112]^ The design includes four suture holes for secure anchoring to the open fascia and a flat, non-protruding structure that enhances stability and minimizes the risk of migration caused by patient manipulation. It is powered wirelessly and functions as a portable therapeutic system. Its compact form factor, ease of implantation, and wireless operation represent significant advancements in usability and safety. Another FDA-cleared wearable TTNS device, currently under premarket clinical investigation, combines neuromodulation and monitoring functions by delivering transcutaneous tibial nerve stimulation through a physiologic closed-loop system that integrates foot EMG sensing for real-time modulation and behavioral tracking via a mobile app to support home-based OAB therapy (Figure 4O ii), and has demonstrated a significantly higher responder rate than sham treatment in a randomized, double-blind, multicenter trial.^[33,113]^
In parallel, gene therapy has emerged as an alternative to treat neurogenic LUT conditions. The urethra’s accessible anatomy facilitates targeted gene delivery to the bladder, making it a suitable site for local therapeutic interventions. Gene therapy is particularly useful for patients resistant to traditional treatments. One major focus has been nerve growth factor (NGF), which plays a critical role in neural regulation and is elevated in patients with OAB.^[114]^ Therapies using NGF antisense peptide nucleic acids (PNAs) combined with TAT peptides have shown potential in reducing NGF expression and alleviating bladder overactivity.^[115]^ Another line of investigation targets big potassium (BK) channels, which modulate detrusor muscle tone and nerve-induced contractions.^[116]^ URO-902, a gene therapy that upregulates BK channel expression, has advanced through Phase 2a clinical trials, showing reductions in micturition frequency and urgency with good tolerability.^[117]^ However, concerns remain about the long-term effects of gene therapies on cellular integrity, necessitating further evaluation in large-scale studies.^[118,119]^
Historically, bladder wall stimulation was first proposed by Magasi in 1980th to address urinary symptoms following SCI.^[120]^ While technological advances have since improved electrode design to mitigate migration and pain, the surgical nature of the procedure still limits its widespread adoption. As an alternative, intravesical electrical stimulation (IVES) has demonstrated benefits for a range of conditions, including acute urinary retention, OAB, and UAB.^[121–123]^ Animal studies report significant reductions in non-voiding contractions and detrusor pressure following IVES therapy.^[124]^ Nevertheless, common side effects such as pain, inflammation, and detrusor muscle thickening pose limitations.^[121]^ Currently, unilateral nerve stimulation is the standard of care in neuromodulation practices. Although bilateral approach has shown promise in small-scale studies,^[125,126]^ their adoption remains limited due to a lack of robust long-term data.^[127]^ One critical challenge in implantable systems such as sacral neuromodulation (SNM) is lead migration. Efforts to address this include modifying electrode hooks,^[128]^ although cost barriers have hindered commercial implementation. Innovations in iTNS devices offer a compelling BlueWind Medical’s design uses suture holes for secure anchoring, while the eCoin device by Valencia Technologies relies on a tissue pocket and broader contact area for stability.^[16]^ Noninvasive transcutaneous treatments, such as spinal cord neuromodulator^[27]^ and wearable tibial neuromodulation system,^[33]^ also offer effective home-based therapeutic options for patients. Together, these developments chart a clear trajectory from early, highly invasive neuromodulation procedures to next-generation systems that prioritize patient comfort, precision therapy, and long-term reliability.
This section presents next-generation bioelectronic platforms that integrate bladder sensing and neuromodulation within a single system. These soft, wireless, and often implantable technologies enable real-time, closed-loop control of bladder function and are primarily in the preclinical stage. Unlike conventional devices, they emphasize tissue conformity, chronic use, and intelligent feedback, offering a promising direction for personalized bladder management.
Optogenetic neuromodulation has emerged as a promising approach to treat bladder dysfunction due to its high precision and minimal impact on surrounding tissues. Optogenetics uses light to control cells (typically neurons) that have been genetically modified to express light-sensitive ion channels. One example of a closed-loop, wireless optogenetic neuromodulation system for the bladder was recently demonstrated.^[30]^ This fully implantable system (illustrated in Figure 5A) comprises several a soft, stretchable strain gauge wrapped around the bladder to measure bladder expansion (filling and voiding), microscale inorganic LEDs (μ-ILEDs) for optogenetic stimulation of neurons in the bladder wall, a wireless circuit to power the system, a thin subcutaneous base station for control of the μ-ILEDs, and a custom software interface for real-time data monitoring. In this system, the strain gauge (SG) is made of a silicone elastomer infused with carbon black, which serves as a resistive sensor that changes resistance as the bladder stretches. The μ-ILED pair emits blue light and is targeted at neurons in the bladder that have been transduced (via viral vectors) to express an inhibitory opsin (Archaerhodopsin-3.0, or Arch).
During operation, the strain gauge continuously monitors bladder volume, and when bladder distension reaches a set threshold, the system triggers the μ-ILEDs to activate the Arch optogenetic channels in the bladder’s afferent nerves or muscle cells, inhibiting bladder contractions. Experiments in an optogenetically engineered mouse model showed that this closed-loop optoelectronic system could precisely monitor bladder filling and modulate bladder function in real time. Importantly, comparisons of bladder mechanics with and without the strain gauge indicated that the device’s presence did not significantly impede bladder expansion (<2% reduction in overall expansion), demonstrating the sensor’s negligible mechanical load (Figure 5A (iii)). This approach exemplifies how wireless optogenetic implants can provide on-demand when the bladder becomes overactive, the device automatically delivers light to suppress contractions, thereby potentially preventing urgency or incontinence. While this particular study was in animals, it lays the groundwork for future closed-loop optogenetic therapies for bladder disorders.
Even though optogenetics neuromodulation provides minimal off-target effects, it requires genetic modification of target neurons, which limits its immediate clinical application. Thus, conventional electrical stimulation remains a mainstay and is being enhanced through new wireless, implantable electronic systems. Researchers have proposed fully implantable electronic stimulators for direct bladder stimulation to treat bladder dysfunction. One such novel system, recently reported, integrates several key low-impedance stimulation electrodes, the ability to simultaneously analyze multiple bladder physiological signals, a closed-loop feedback mechanism to modulate the voiding cycle, and a wireless, battery-free platform in a fully implantable design.^[26]^ In essence, this device combines bladder sensing and stimulation in one wireless unit. The implantable system (illustrated in Figure 5B) consists of three interconnected an electronic web of sensors that lays over the bladder surface, an electronic thread that interfaces with nerves or muscles, and a wireless power circuit that supplies energy and communication (Figure 5B (i)). In preclinical testing, investigators created a detrusor underactivity (DUA) model in animals to simulate an underactive bladder condition (confirmed via histology, Figure 5B (ii)). Using the implanted system, they applied electrical stimulation to the bladder and associated nerves in both healthy (sham) and DUA model groups. The results were the DUA model animals, when electrically stimulated, achieved voiding efficiency and patterns similar to the healthy controls. In other words, the electrical neuromodulation delivered by the wireless implant restored near-normal bladder emptying in animals with otherwise poor bladder contractility (Figure 5B (iii),(iv)). This demonstrates the potential of a closed-loop electrical stimulator to sense inadequate bladder emptying and then stimulate the bladder to empty appropriately. The entire system operates without batteries (drawing power wirelessly), which is advantageous for long-term implantation.
Chronic (long-term, continuous) monitoring of bladder activity can significantly improve clinical diagnosis and guide therapy selection for patients with urinary dysfunction. It can also alert patients or healthcare providers when the bladder needs to be emptied, which is particularly useful for those who lack sensation. A recent example is a wireless, implantable system designed for chronic bladder monitoring after bladder surgery.^[19]^ As shown in Figure 5C, after a partial cystectomy (surgical removal of part of the bladder), a stretchable strain-gauge sensor is wrapped around the bladder and connected via a helical coil wire to a small wireless module (Figure 5C (i), (ii)). This system continuously monitors bladder volume changes (via SG sensor) and transmits the data wirelessly, unlike conventional urodynamics which only provides snapshots of bladder function in a clinical setting.
To evaluate bladder recovery after surgery, researchers use this system in animal models with partial cystectomy versus control animals with normal bladders. The wireless strain sensor tracks the filling and voiding cycles in real time. In the partial bladder models, the data reveals differences in bladder wall tension (resistance) before and after voiding compared to normal bladders. Over time, as the partial cystectomy bladders healed, the number of voids per day gradually stabilize to a normal range, indicating recovery of function (Figure 5C (iii), (iv)). The system is able to monitor bladder function in non-human primates for up to 8 weeks, providing continuous pressure data throughout the recovery period. While the in vivo demonstrations utilize non-degradable SG materials, a biodegradable strain sensor is also developed and validated in benchtop studies. This degradable option has the potential to reduce long-term foreign body response (FBR) and eliminate the need for secondary surgical removal in future applications. This level of longitudinal monitoring is not possible with traditional methods and may have broader applications for tracking healing and function after other types of urological surgeries.
Wireless and implantable bioelectronic systems like those described above are being developed to offer bifunctional capabilities – both bladder monitoring and neuromodulation in one platform. By integrating advanced features such as closed-loop feedback control and even optogenetic or pharmacological components, these systems enable real-time bladder state detection and personalized therapeutic intervention. The ultimate goal of such innovations is to improve patient outcomes by providing continuous sensing a problem (e.g., dangerous bladder pressure or inappropriate contraction) and automatically delivering a therapy (stimulation or drug) to correct it. Although preclinical studies in animal models have shown promising results, further research and refinement are required to evaluate long-term efficacy, safety, and clinical usability of these systems. One ongoing challenge is the foreign body response – implanted devices can elicit tissue reactions and fibrous encapsulation that diminish their performance over time. Incorporating advanced biomaterials (such as anti-fouling coatings, bioresorbable elements, or immunomodulatory materials) or cell-based synthetic biology^[129]^ is expected to help mitigate FBR, thereby enhancing the long-term biocompatibility and functionality of these bladder implants. Multimodal bladder sensors face the inherent challenge of signal overlap when exposed to simultaneous physical stimuli, such as pressure, strain, and body motion. To address this, recent studies have proposed several decoupling strategies.^[130]^ Material-level selectivity^[131]^ leverages sensing layers tuned to respond preferentially to specific inputs, such as piezoresistive films for pressure versus thermoresponsive polymers for temperature. Structural isolation,^[132]^ such as spatial separation or multilayer stacking, physically segregates different sensing functions. Additionally, computational methods, including signal processing^[133]^ and machine learning-based classification,^[134]^ can separate composite signals during post-processing. While most current bladder systems focus on a single sensing mode, future smart platforms will likely integrate such decoupling techniques to improve specificity and reliability under real-world physiological conditions. Table 4 summarizes representative sensor and stimulator components in emerging bioelectronic bladder systems, detailing their material composition, fabrication approaches, actuation or sensing mechanisms, and resulting performance metrics. This comparative overview highlights how structural design and processing strategies influence device-level functionality, including stretchability, signal quality, responsiveness, and biocompatibility, which provides guidance for future device and technology development.
Over the past decade, an increasing number of devices have been developed that offer advanced capabilities for monitoring bladder activity and treating LUT diseases. Table 1 outlines key features of existing devices, providing a summary of the major innovations discussed. While the majority of existing devices are still tethered or wired, recent progress on wireless technologies means that an increasing number of systems now feature wireless communication and make them more user-friendly.
For bladder volume monitoring, ultrasound remains a well-established, noninvasive technology that is widely used in clinical settings due to its safety and familiarity. However, its use typically requires well-trained clinicians to operate the equipment.^[18]^ Recently, more flexible, wearable ultrasound devices have been fabricated that can directly attach to the abdomen and take ultrasound images of the bladder.^[18,135]^ Clinical trials of these conformable ultrasonic biosensors are underway and hold a promising potential for the future clinical translation, laying the groundwork for the development of wearable ultrasound devices. In addition, NIRS- and bioimpedance-based technologies are also being explored as effective methods for the volume monitoring. For bladder pressure monitoring, current biomedical devices can be categorized by their locations (intravesical versus suburothelial). However, major limitations of the current pressure monitors include the risk of infection and lower urinary tract damage, since most technologies still involve invasive components. Additionally, artifacts may happen due to patient movement or unexpected pressure fluctuations from the abdomen, presenting another challenge. Chronic bladder monitoring is crucial, for instance following surgical interventions, to ensure safe recovery and optimal timing of therapies. To address this need, a fully implantable bioelectronic system has shown potential for long-term bladder monitoring, with validation studies in rodent models (30 days) and non-human primates (8 weeks) suggesting its effectiveness in delivering personalized treatment and rehabilitation strategies for human counterparts.^[19]^ Furthermore, emerging new biomaterials with properties like excellent biocompatibility, antibacterial effects, high stretchability, mechanical durability, and biodegradability—along with other unique features—show great promise as device-tissue interfaces for in vivo implant applications. While still in the early stages of research, these advanced materials could enable long-term integration of sensors and electrodes with the bladder, reducing complications and enhancing functionality.
Neuromodulation remains a cornerstone for treating LUT dysfunction, but conventional methods have drawbacks. Sacral nerve stimulators (SNS) and percutaneous tibial nerve stimulation (PTNS) are effective but invasive or require frequent clinic visits, which can reduce patient compliance. Patients with implanted SNS devices must undergo regular office visits for device reprogramming and periodic surgeries to replace depleted batteries, while PTNS requires frequent (e.g., weekly) sessions that can be burdensome. Most current neuromodulation systems rely on batteries, many of them are non-rechargeable and eventual surgical replacement. Fortunately, recent advancements have introduced significant improvements to neuromodulation devices, addressing many of these limitations (see Figure 1 for details). The latest FDA-approved sacral neuromodulation products include systems that are recharge-free for up to 15–20 years (and rechargeable versions that last even longer). They also come with patient-operated remote controls, allowing personalized, adjustable therapy without an office visit. Additionally, two implantable tibial nerve stimulation devices have received FDA approval.^[136]^ These lightweight, wearable implants provide long-term therapy for OAB with only a one-time minimally invasive procedure. They are powered by external rechargeable batteries, eliminating the need for repeated surgeries to replace batteries. With the goal of enhancing the accessibility of neuromodulation, a recent landmark randomized controlled trial demonstrated that individuals with spinal cord injury and neurogenic bladder who self-administered transcutaneous tibial nerve stimulation were able to reduce their reliance on overactive bladder medications by more than 50%—a benefit observed in nearly all participants in the treatment group.^[137]^ With these innovations, sacral and tibial nerve stimulation continue to be effective therapeutic approaches and have become more convenient and sustainable options in bladder care.
Although much progress has been made, open challenges remain especially in achieving reliable, chronic monitoring and neuromodulation that meet long-term therapeutic needs for patients with neurogenic bladder dysfunction. Current clinical instruments and wearable bladder monitoring systems have reached a good level of maturity; however, their accuracy and consistence are not yet sufficient to significantly improve the patient’s life quality.^[138]^ Encouragingly, technological progress in several areas is poised to bridge this gap.
Development in wearable ultrasound systems,^[139,140]^ deep-tissue sensing approaches,^[141,142]^ device miniaturization, and long-term wireless power and data communication techniques^[19]^ promise to yield future urological devices with unprecedented capabilities. These next-generation devices will likely incorporate features such as continuous chronic monitoring of bladder volume and pressure, serial assessment of biomechanical properties of bladder tissue (e.g., compliance), noninvasive neuromodulation therapies, and advanced human–machine interfaces. Such systems could be used not only in clinics but also by patients at home, enabling telemedicine and remote management of bladder conditions.
Emerging wireless implantable bioelectronic systems have proven utility in monitoring and neuromodulation treatments in live animal models and with levels of technical maturity. They hold promising potential for broad deployment to the urology community in the near future. However, critical challenges remain in translating these advances to routine clinical practice. Ensuring chronically stable biocompatibility (minimizing fibrotic encapsulation), achieving high spatiotemporal resolution and scalability of sensing/stimulation, and incorporating advanced modalities for complex neuro-urological disorders are all active areas of research. Device biocompatibility is of paramount foreign-body responses can impair long-term function, so strategies to minimize tissue reactivity are needed. Recent work has shown promise in this regard, including the development of novel anti-FBR coatings and materials,^[143]^ the use of biofluid barriers and hydrogels to insulate devices,^[144]^ and hybrid cell encapsulation strategies that “hide” the device from the immune system.^[145]^ Integrating these biomaterial innovations with implantable devices may achieve a degree of chronic stability in vivo, with negligible FBR.
Researchers are also pushing the envelope by combining multiple modalities in single platforms. A recent work demonstrated a multimodal neuromodulation system that integrates electronic, optoelectronic, and microfluidic components, and supports AI-based algorithms, on-demand drug delivery, and multimodal sensing for autonomous closed-loop operation.^[146]^ This platform can simultaneously perform measurements (e.g., sensing bladder volume or pressure) and deliver therapies (electrical stimulation, light, or pharmacological agents), essentially functioning as a smart bladder pacemaker. Such technology could be adapted to address a range of complex neurogenic bladder dysfunctions that require combination therapy. Furthermore, novel mechanical design concepts (like fractal-inspired stretchable electronics) have yielded extremely stretchable implants capable of conforming to organs like the bladder that undergo large volume changes.^[147–149]^ These designs can potentially support hundreds or even thousands of sensors or micro-stimulators distributed across the bladder surface, enabling high-fidelity recording and stimulation without interfering with natural bladder dynamics. Hybrid mechanical–bioelectrical sensors^[26,48]^ are increasingly explored for urological devices due to their improved mechanical durability and electrical performance during bladder expansion and contraction. Emerging fabrication techniques, including laser-induced patterning,^[150]^ direct ink writing,^[151]^ and 3D freeform microprinting,^[152]^ enable precise integration of deformable sensors and functional circuits onto soft, curved bladder tissues. These approaches reduce mechanical mismatch, enhance biocompatibility, and support stable signal acquisition in vivo.^[153]^ Moreover, fully standalone, stretchable sensing platforms^[30]^ are being developed to allow real-time monitoring without rigid hardware, enabling continuous, unobtrusive use in both clinical and at-home environments.
In summary, progress in urological technology—driven by a convergence of interdisciplinary efforts—will accelerate the pace of discovery in urology. These discoveries, in turn, will promote the development of widely accessible urological technologies as tools for the healthcare community to address a wide range of challenging bladder-related conditions. The integration of advanced engineering with medical insight promises to transform the management of non-malignant and neurogenic bladder disorders in the coming years.
In this review, we provide a comprehensive overview of recent progress in urological technologies that have emerged over the past decade for monitoring and treating a variety of challenging bladder and LUT diseases, including but not limited to urinary incontinence, overactive bladder, detrusor sphincter dyssynergia, and others. A range of advanced biomedical devices and emerging engineering platforms are introduced, from wired electrical stimulators and flexible optogenetic devices to wireless, closed-loop bioelectronic systems. These emerging systems may serve as effective new avenues of care for patients with many types of complex bladder conditions, providing continuous monitoring and targeted neuromodulation therapies that can improve patient outcomes. The convergence of innovation in materials science, electronics, and bioengineering—combined with clinical expertise in urology—is driving the development of next-generation bladder management technologies. As these multidisciplinary efforts continue, they will accelerate discovery and facilitate translation of these urotechnologies into widely accessible tools for the urology community, ultimately improving the care of patients with non-malignant and neurogenic bladder disorders.