Multilevel Cu-LIG\nTactile Sensing Arrays for 3D Touch\nHuman–Machine Interaction

High-performance flexible tactile sensors have attracted\nsignificant\nattention in the domains of human–machine interactions. However,\nthe efficient fabrication of sensors with highly sensitive responses\nover a broad load range still remains a challenge. Here, we propose\na one-step laser writing route to construct a distinctive multilevel\npiezoresistive structure, consisting of Cu nanoparticle-doped graphene\nprotrusions and surrounding porous Cu sheets. This multilevel structure\nenables the assembled tactile sensors to exhibit superior sensitivity\nat both low-pressure (1468 kPa<sup>–1</sup> at 0–200\nkPa) and high-pressure (1345 kPa<sup>–1</sup> at 600–800\nkPa) stimulations. Its enhancement mechanism for piezoresistive sensing\nhas been investigated. The programmable laser writing process facilitates\nthe development of human–machine interaction devices that recognize\nmultidimensional gestures such as sliding, clicking, and pressing.\nThis advancement serves to promote the development of high-performance\ninteractive sensing technologies.