Laser Direct Writing of Ultrahigh Sensitive SiC-Based Strain Sensor Arrays on Elastomer toward Electronic Skins

Electronic skins (e-skins) have been widely investigated as important platforms for healthcare monitoring, human/machine interfaces, and soft robots. However, mask-free formation of patterned active materials on elastomer substrates without involving high-cost and complicate processes is still a grand challenge in developing e-skins. Here, SiC-based strain sensor arrays are fabricated on elastomer for e-skins by a laser direct writing (LDW) technique, which is mask-free, highly efficient, and scalable. The direct synthesis of active material on elastomer is ascribed to the LDW-induced conversion of siloxanes to SiC. The SiC-based devices own a highest sensitivity of ≈2.47 × 10⁵ achieved at a laser power of 0.8 W and a scanning velocity of 1.25 mm s⁻¹. Moreover, the LDW-developed device provides a minimum strain detection limit of 0.05%, a small temperature drift, and a high mechanical durability for over 10 000 cycles. When it is mounted onto human skins, the SiC-based device is able to monitor external stimuli and human health conditions, with the capability of wireless data transmission. Its potential application in e-skins is further proved by an LDW-fabricated device having 3 × 3 SiC sensor array for tactile sensing.