Sensing — Physical AI Tactile Sensor Fabrication

Applied Technologies

1. Laser Interference Lithography
Using two coherent laser beams recombined on the substrate, this mask-free process forms periodic micro/nano-scale patterns (1D gratings, 2D hole arrays) in a single exposure via a Lloyd's-mirror-type 355 nm UV nanosecond laser system. It defines the fine surface texture that governs a tactile sensor's sensitivity, enabling fast, low-cost, large-area nanopatterning without photomasks or complex lithography equipment.

2. Laser-Induced Graphene (LIG)
Direct laser irradiation of a carbon-containing surface converts it locally into a porous graphene structure — no chemical treatment or high-temperature processing required. Using a nanosecond near-infrared (NIR) laser, conductive carbon networks can be selectively written only where needed, giving high design freedom. The resulting porous graphene layer exhibits pressure/contact-dependent resistance change, making it directly usable as the sensing material in a tactile sensor.

3. AgNW Patterning (Silver Nanowire Patterning on PDMS)
Silver nanowires (AgNW) are first assembled into a transparent conductive network via vacuum filtration, then transferred onto a flexible PDMS substrate to form stretchable electrodes. Combined with laser patterning, conductive pathways can be selectively defined only where needed — enabling tactile-sensor electrodes that are simultaneously flexible, highly transparent, and electrically conductive.