Open AccessGuiding magnetic liquid metal for flexible circuit
Author(s) -
Feng Chen,
Qing Yang,
Jiale Yong,
Chao Shan,
Jingzhou Zhang,
Xun Hou,
Feng Chen
Publication year - 2021
Publication title -
international journal of extreme manufacturing
Language(s) - English
Resource type - Journals
eISSN - 2631-8644
pISSN - 2631-7990
DOI - 10.1088/2631-7990/abeda3
Subject(s) - materials science , magnetic field , flexible electronics , substrate (aquarium) , printed circuit board , optoelectronics , short circuit , electronic circuit , laser , composite material , electrical engineering , optics , voltage , engineering , physics , oceanography , quantum mechanics , geology
Liquid metal (LM) has potential applications in flexible electronics due to its high electrical conductivity and high flexibility. However, common methods of printing LM circuits on soft substrates lack controllability, precision, and the ability to repair a damaged circuit. In this paper, we propose a method that uses a magnetic field to guide a magnetic LM (MLM) droplet to print and repair a flexible LM circuit on a femtosecond (fs) laser-patterned silicone surface. After mixing magnetic iron (Fe) particles into LM, the movement of the resultant MLM droplet could be controlled by a magnetic field. A patterned structure composed of the untreated flat domain and the LM-repellent rough microstructure produced by fs laser ablation was prepared on the silicone substrate. As an MLM droplet was guided onto the designed pattern, a soft LM circuit with smooth, uniform, and high-precision LM lines was obtained. Interestingly, the MLM droplet could also be guided to repair the circuit broken LM lines, and the repaired circuit maintained its original electrical properties. A flexible tensile sensor was prepared based on the printed LM circuit, which detected the bending degree of a finger.