Pneumatic Actuation of a Liquid Metal Circuit Embedded in an Elastomer Body

Abstract

In the electronics field there has been research into fabrication of flexible and stretchable electronic components, such as wires, sensors, and capacitors. This report aims to contribute to this niche of research by creating a pneumatically actuated reconfigurable liquid metal-based circuit. This was done by incorporating a milli-fluidic channel containing a liquid metal (gallium (Ga)) into a silicone elastomer body. The Ga channels served as the circuit. To reconfigure the circuit, millifluidic air channels were fabricated alongside the Ga channels. When inflated, these air channels would close the Ga channels and manipulate the movement of Ga, thereby altering the flow of an electric current running through the Ga channel. Using CAD, the prototype was designed, then the mould was 3D printed. Afterwards, the silicone was casted onto the mould and the 3D milli-fluidic channels were filled with their respective components. This project took on an iterative approach, where different designs for the silicone body and milli-fluidic channels were made and analysed to optimise functionality of the prototypes. Several issues regarding fabrication and performance of the device were addressed, and improvements for further research were suggested. The outcome of this research found that the concept of pneumatically manipulating a Ga-based circuit is possible. Also, this project found that by changing the design of the device, the interaction between the Ga and air channels are adjusted, thus new functions for the device can be designed. This evidence indicates that this device is quite versatile as a replacement or additional component within electronics.