Fabrication of Flexible Copper Microelectrodes Using Laser Direct Writing for Sensing Applications

The fabrication of flexible electronics has gained extensive attention due to the growing demand of flexible devices. Among various methods, laser direct writing technology has emerged as a promising approach due to its advantages of high processing accuracy and simplicity. This research focuses on the preparation of copper microelectrodes using laser‐induced reduction of CuO nanoparticles (Cu NPs) on polyethylene terephthalate films. First, the influence of various parameters on the conductivity of the copper microelectrodes is investigated. Second, flexible copper microelectrodes with a minimum resistivity of 62.29 μΩ cm and an adhesion grade of 4B level are successfully fabricated. Building upon these results, a capacitive pressure sensor is developed with optimal sensitivity of 3.99 Pa−1, good hysteresis of 3.99%, and response and recovery times of 1.2 and 1.3 s, respectively. Repeatability tests confirm the sensor's stability and fatigue resistance. This research provides valuable insights for the production of flexible sensors. Copper microelectrodes based on PET substrates are fabricated using laser direct writing technology to induce the reduction of CuO nanoparticles, achieving a minimum resistivity of 62.29 μΩ cm and an adhesion grade of 4B level. Furthermore, a capacitive pressure sensor based on these copper microelectrodes is fabricated and exhibits pretty good sensing performance upon testing.