Liquid-based tactile sensing array with adjustable sensing range and sensitivity by using dielectric liquid

• We present a novel tactile sensing array with adjustable sensing ranges and sensitivity.
• The sensing range can be adjusted between 0.42–1.12 N and 0.05–0.29 N.
• The sensitivity of sensing element at 0.05–0.29 N force range is 1.88 times comparing to that at 0.42–1.12 N force range.
• The sensing range and sensitivity can be adjusted during the sensing process.

This paper presents a novel tactile sensing array with adjustable sensing range and sensitivity. The sensing array consists of a deformable PDMS spacer layer, two Al glass substrates, and two dielectric liquids. The two dielectric liquids form a composite dielectric material, which is a low-dielectric-constant (ɛr) droplet covered with a high-ɛr liquid. The composite dielectric material is sandwiched between the upper and lower electrodes. By adjusting the electric flux passing through the electrodes, the contact angle of the droplet can be controlled. The sensing range and sensitivity were adjusted by varying the droplet shape. The results show that the device's sensing range can be adjusted in the ranges 0.05–0.29 N and 0.42–1.12 N. Compared with other devices, which are often used in a large force range, this device can be used in a smaller force range and provides 1.88 times greater sensitivity. Besides, the sensitivity can be adjusted during the sensing process.