Preliminary investigation into low-cost stretch sensors for stomach deformation measurement

Physical simulation of gastric tract motility, through the use of controlled flexi-walled reactors, can benefit from measured feedback of the amount of stretch that regions of the deformable membrane wall undergo. Appropriate sensors need to be at least as flexible as the surface they are mounted on, and have the ability to stretch to the same extent. One method for measuring the stretch of highly flexible membrane walls is through the use of conductive ionic fluids encased in a flexible elastomer. A change in resistance can be measured between two terminals of the ionic liquid pathway as the sensor strip undergoes stretch deformation. A simple, low-cost approach to fabricating this form of sensor is to encase a conductive saline solution in a highly flexible silicone tube, with electrodes placed in contact with the fluid at the two ends of the sealed tube. Initial results indicate that this basic approach provides good stability and repeatability of resistance measurement readings during stretching. Further testing of the characteristics of this type of sensor is required to properly assess its capabilities against commercial stretch sensors and state-of-the-art devices.