Fabrication and test of a tube shaped e-skin sensor on a colon simulator

Thin film stretchable sensors are believed to have great applications on devices with curved surface. Among them, electrical skin (e-skin) sensors for pressure measurement have the potential to provide protection to human body by feeding back the contact pressure. One of the applications is to monitor the contact pressure from colonoscope to the colonic wall during a colonoscopy to prevent perforation and hemorrhaging. Many researches have been reported about highly flexible and stretchable e-skin sensors. However, no effort has been made to investigate its performance in a colon simulator. In this work, we developed a new technique to make ultra-thin, highly stretchable electrodes on thin films. Then we successfully built a three-layer tube shaped tactile sensor with high conformability and stretchability. We then investigated the pressure generated by various bending curvatures on a colonoscope. Finally, we performed a real-time pressure measurement with the whole sensing system on a fake colonoscope in a colon-simulator. The measured pressure was obtained and visualized on a computer screen. These experiments validated the applicability of the designed sensor and revealed the actual stress distribution on a tube shaped e-skin sensor array in a colon-simulator. This research could be the starting point of the effort on upgrading the strategies of colonoscopy for safer operations and could provide new routines to optimize tactile sensor design for other medical applications.