Universal assembly of liquid metal particles in polymers enables elastic printed circuit board.

Lee, Wonbeom; Kim, Hyunjun; Kang, Inho; Park, Hongjun; Jung, Jiyoung; Lee, Haeseung; Park, Hyunchang; Park, Ji Su et al. · Science · 2022

basic_science · Level V

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Abstract

An elastic printed circuit board (E-PCB) is a conductive framework used for the facile assembly of system-level stretchable electronics. E-PCBs require elastic conductors that have high conductivity, high stretchability, tough adhesion to various components, and imperceptible resistance changes even under large strain. We present a liquid metal particle network (LMP<sub>Net</sub>) assembled by applying an acoustic field to a solid-state insulating liquid metal particle composite as the elastic conductor. The LMP<sub>Net</sub> conductor satisfies all the aforementioned requirements and enables the fabrication of a multilayered high-density E-PCB, in which numerous electronic components are intimately integrated to create highly stretchable skin electronics. Furthermore, we could generate the LMP<sub>Net</sub> in various polymer matrices, including hydrogels, self-healing elastomers, and photoresists, thus showing their potential for use in soft electronics.