Liquid metal electronic devices

Combining metallic and liquid characteristics, liquid metals have shown ultimate flexibility, high electrical and thermal conductivity, and unique interfacial chemistry. The utilization of liquid metals as stretchable conductors, connecting electronic components to fabricate flexible electronic devices, is one of the most promising applications demonstrated for liquid metals. This chapter will introduce several typical applications of liquid metal electronic devices. At first, according to the attachment substrates of liquid metals, liquid metal electronic devices can be divided into several categories, including implantable and epidermal biomedical sensors, wearable smart fabrics, paper-based flexible circuits, and curved conformal circuits. This chapter will introduce the manufacturing methods and application effects of these electronic devices, especially the unique advantages of liquid metals. Then, several optoelectronic and thermoelectric devices will also be introduced, in which liquid metals provide effective connections between functional components. Finally, challenges, the prospected future, and developing motifs of each type of liquid metal electronic device are discussed.