All-soft multiaxial force sensor based on liquid metal for electronic skin

Abstract

Abstract Electronic skin (E-skin) capable of detecting various physical stimuli is required for monitoring external environments accurately. Here, we report an all-soft multiaxial force sensor based on liquid metal microchannel array for electronic skin applications. The proposed sensor is composed of stretchable elastomer and Galinstan, a eutectic gallium-indium alloy, providing a high mechanical flexibility and electro-mechanical durability. Liquid metal microchannel arrays are fabricated in multilayer and positioned along a dome structure to detect multi-directional forces, supported by numerical simulation results. By adjusting the height of the dome, we could control the response of the multiaxial sensor with respect to the deflection. As a demonstration of multiaxial force sensing, we were able to monitor the direction of multidirectional forces using a finger by the response of liquid metal microchannel arrays. This research could be applied to various fields including soft robotics, wearable devices, and smart prosthetics for artificial intelligent skin applications.

Keywords

• Electronic skin
• Force sensor
• Multiaxial sensor
• Liquid metal
• 3D printing