Design and Fabrication of Soft Artificial Skin Using Embedded Microchannels and Liquid Conductors

TLDR

The study presents the design, fabrication, and calibration of a highly compliant artificial skin sensor. The sensor is built from multilayered microchannels in an elastomer matrix filled with conductive liquid, fabricated via layered molding and casting of silicone rubber with 3‑D printed molds, yielding 25 mm × 25 mm × 3.5 mm devices with 200 µm × 300 µm channels. Testing shows the prototype exhibits linear strain response, nonlinear pressure response, repeatable signals, a modulus of ~63 kPa, and remains functional up to ~250 % strain.

Abstract

We describe the design, fabrication, and calibration of a highly compliant artificial skin sensor. The sensor consists of multilayered mircochannels in an elastomer matrix filled with a conductive liquid, capable of detecting multiaxis strains and contact pressure. A novel manufacturing method comprised of layered molding and casting processes is demonstrated to fabricate the multilayered soft sensor circuit. Silicone rubber layers with channel patterns, cast with 3-D printed molds, are bonded to create embedded microchannels, and a conductive liquid is injected into the microchannels. The channel dimensions are 200 μm (width) × 300 μm (height). The size of the sensor is 25 mm × 25 mm, and the thickness is approximately 3.5 mm. The prototype is tested with a materials tester and showed linearity in strain sensing and nonlinearity in pressure sensing. The sensor signal is repeatable in both cases. The characteristic modulus of the skin prototype is approximately 63 kPa. The sensor is functional up to strains of approximately 250%.