# Toward virtual bladder: real-time bladder volume monitoring with flexible AuCNT strain sensors

## TL;DR

Researchers developed a flexible sensor to monitor bladder volume in real time, aiming to improve diagnostics and treatment for bladder dysfunction.

## Contribution

A three-channel flexible AuCNT strain sensor was designed and tested for accurate bladder volume monitoring.

## Key findings

- The AuCNT sensor showed high sensitivity and spatial accuracy in capturing bladder expansion.
- A preliminary Virtual Bladder model was created for real-time visualization of volume changes.
- The three-channel design outperformed single-channel approaches in spatial accuracy.

## Abstract

Digital twin technology holds considerable potential for personalized diagnostics and treatment of bladder dysfunction, particularly neurogenic conditions such as underactive bladder (UAB). In this study, to address the need for precise monitoring, we introduce a flexible, stretchable strain sensor composed of gold-coated carbon nanotubes (AuCNTs) embedded in Ecoflex. We specifically designed a three-channel configuration to capture anisotropic expansion and evaluated the sensor’s performance using both two-dimensional balloon models and ex-vivo three-dimensional porcine bladder models. As a result, the AuCNT sensor demonstrated high sensitivity, and the three-channel design significantly enhanced spatial accuracy compared to single-channel approaches. Based on these measurements, we created a preliminary “Virtual Bladder” model that provides dynamic, real-time visualization of bladder volume changes. While our current model requires further development to incorporate multimodal data and anatomical variability, it serves as a foundational step towards developing advanced digital twin frameworks and closed-loop neuromodulation systems for bladder dysfunction.