Reconfigurable logic devices connected with laser-sintered liquid metal nanoparticles

In this paper we demonstrate the use of liquid metal nanoparticles as electrical traces between logic gates. When first deposited, films of nanoparticles are non-conductive, despite their metallic composition. Nanoparticle films can be coalesced into conductive traces using an infrared laser. We demonstrate the utility of this approach by using laser-patterned films to connect NAND gates in different circuits, creating an OR gate and a light-sensitive thermostat. We also show that patterned films can be removed, making the devices re-usable and re-programmable. Liquid metal nanoparticle-based devices may be used to create environmentally responsive devices in the future.

I. Introduction

Although many different types of sensors exist for different physical phenomena, the information collected by these sensors is generally processed by fixed logic devices. In contrast to this approach, we hypothesize that a new class of environmentally-responsive electronic circuits that adjust functionality and programming in response to changes in environmental conditions are possible [1]. Our research is based on liquid-metal alloys, which can be used to create electrical connections in highly deformable systems [2], [3]. Multiple approaches to patterning liquid metals have previously been demonstrated, including injection into microchannels, ablation of a film of native liquid metal, and extrusion of liquid metal onto a surface [4]. Reconfigurable devices made from liquid metals have also been demonstrated [5], [6]. These devices use the movement of liquid metals within microchannels to achieve adjustable functionality.