A Nanocomposite-Based Stretchable Deformation Sensor Matrix for a Soft-Bodied Swallowing Robot

This paper presents the design, fabrication, and calibration of a stretchable deformation sensor matrix based on carbon nanotube filled Ecoflex composite. The sensor is used to measure the conduit surface deformation of a soft-bodied swallowing robot. The sensor matrix contains four strips, and 12 sensor pads for each strip. It is made first in a flat sheet, then rolled into a cylindrical shape, and finally embodied in the conduit of the swallowing robot. Each pad of the sensor matrix is tested at room temperature with the pressure range of 0-58 kPa applied to inflate the chambers of the conduit body. The sensor pads are tested up to 450% strain at maximum. The results show that the sensor has an average resistance variation of 120%/kPa in the deformation measurement, the relationship between the resistance and strain is linear, within the working range the gauge factor is 2.2 of the linearity of R
²
=0.9677$ and the resolution of the deformation measurement is 0.1 mm. Further experiments are carried out after the sensor matrix is embodied into the swallowing robot. The initial result suggests that the multi-walled nanotubes Ecoflex surface deformation sensor is reliable and able to deliver required sensing.