Liquid metal wiring technique shows promise for flexible electronics

This technique from a team at Yokohama National University is claimed to offer new options for creating bendable, stretchable, and highly conductive circuits for devices including wearable sensors and medical implants. Their study is detailed in Nanomaterials.

In a statement, corresponding author Shoji Maruo, a professor at the Faculty of Engineering of Yokohama National University, said: “Conventional wiring technologies rely on rigid conductive materials, which are unsuitable for flexible electronics that need to bend and stretch.”

Liquid metals show promise as an alternative to rigid materials but using them comes with challenges.

“Liquid metals provide both flexibility and high conductivity, yet they present issues in wiring size, patterning freedom, and electrical resistance of its oxide layer,” said Masaru Mukai, an assistant professor at the Faculty of Engineering and the study’s first author.

The research team addressed these limitations by adapting a bubble printing method to pattern liquid metal colloidal particles of eutectic gallium-indium alloy (EGaIn). Bubble printing is an advanced technique for creating precise wiring patterns directly onto surfaces, especially on non-traditional or flexible substrates, using particles that are moved by the flow generated by bubbles.