Soft artificial skin with multi-modal sensing capability using embedded liquid conductors

We describe the design, fabrication and calibration of a highly compliant mechanism to be used as an artificial skin sensor. The artificial skin sensor consists of multilayered mircochannels filled with a conductive liquid capable of detecting multi-axis strains and contact pressure. A novel manufacturing method composed of layered molding and casting processes was proposed to fabricate a multilayered soft sensor circuit. Silicone rubber layers with channel patterns, cast with 3D printed molds, were bonded to create embedded microchannels, and a conductive liquid was injected into the microchannels. The channel dimensions are 200µm × 200µm for strain sensing and 500µm (width) × 200µm (height) for pressure sensing. The size of the sensor is 25mm × 25mm, and the thickness is approximately 3.5mm. The prototype was tested with a materials tester and showed linearity in strain sensing and nonlinearity in pressure sensing. The sensor signal was repeatable in both cases.