Excimer laser photoablation with in-situ masking for fabrication of stretchable pressure sensor arrays

Stretchable sensor arrays have applications in robotics, structural health monitoring (SHM) devices, and electronic textiles applications where they can be mounted directly on nonplanar surfaces. For robotics, pressure sensor arrays mimic the human sense of touch, providing sensory feedback to help the robot move in a controlled manner. Our research investigates a novel microelectronic process sequence for fabricating stretchable capacitive pressure sensors on polymer substrates, where metal patterns serve both as functional electrode layers and as in-situ masks for excimer laser photoablation. This approach reduces the number of photomasks and processing steps, is scalable for large-area arrays, and is adaptable for a variety of materials and designs. Individual 200μm-sized sensors show a capacitance change of 60fF with an applied pressure of 500kPa. Pressure sensors are fabricated as a 4×4 array connected with redundant stretchable interconnects to demonstrate successful readout of different pressure profiles.