Soft water-filled sensing chambers to improve sensitivity and range of measurements

In this work, we propose soft water-filled sensing chambers as the add-on sensing elements for the fingers of prosthetic hands and other similar applications requiring contact sensing. From the experimental results, the soft water-filled sensing chambers exhibit good performance in linearity, hysteresis, stability, etc., like their pneumatic counterparts. The results also demonstrate that the water-filled sensing chambers perform better in the sensitivity and range of measurements, compared with soft pneumatic sensing chambers. This benefit greatly enhances the capability of miniaturization for soft-chamber-based sensors so that their applications can be widely extended, especially for those applications having low-footprint requirement, such as a low-profile finger cot, which is designed as add-on force sensors for existing prosthetic hands and enable them with haptic feedback.