Dual-Band Laser Selective Etching for Stretchable and Strain Interference-Free Pressure Sensor Arrays

Stretchable pressure sensor arrays are ideal for biomimetic electronic skin (e-skin). However, conventional pressure sensors exhibit noticeable strain interference when stretched. This article introduces an advanced fabrication method based on dual-band laser selective etching to create stretchable pressure sensor arrays free from strain interference. An intact sensitive film is sandwiched between the top and bottom electrodes and then etched into separate sensing cells. Silicone gel with an extremely low Young's modulus (0.157 kPa) is employed as the strain buffer layer, filling the space within sensing cells to absorb device strain during stretching. The pressure sensor arrays demonstrate exceptional interference-free performance, with the resistance of sensing cells remaining unchanged under strains exceeding 20%. Pressure sensor arrays of 32 x 32 units are manufactured, showcasing a resistive response time of approximate to 40 ms during compression and 20 ms during release, along with a sensitivity of 0.7702 kPa-1 within the range of 1-70 kPa. Finally, the sensor arrays are integrated into a robotic hand as biomimetic e-skin, coupled with deep learning algorithms, successfully identifying static and dynamic pressure distributions and achieving an average precision rate of over 99% in recognizing 2D shapes and objects. Stretchable and high-density pressure sensor arrays are key to advancing healthcare and human-machine interfaces. To overcome strain interference, researchers propose a solution for large-scale integration using advanced dual-band laser selective etching. This innovative method efficiently prepares stretchable and high-density pressure sensor arrays that incorporate deep learning to meet the critical needs of bionic skin and next-generation smart technologies. image