Bio-inspired dry adhesive pads using multi-walled carbon nanotube/polydimethylsiloxane composites for efficient wafer transfer robot arms in smart factories†

The development of dry adhesive pads (DAPs) is essential to prevent wafer detachment from high-speed wafer-transfer robot arms. However, polydimethylsiloxane (PDMS)-based DAPs, which are insulating elastomers, generate residual charges inside DAPs. These cause charge accumulation and electrostatic interactions between the DAP and the wafer interface. Furthermore, at a high processing temperature of >300 °C, the adhesive and mechanical strengths of conventional DAPs are degraded because of their low thermal and mechanical stability. In this study, we developed bio-inspired DAPs (BDAPs) with various shapes (hole, cylinder, and line patterns) and different contact areas (20, 40, and 60%) through systematic investigations to determine optimized patterns and shapes for different motions. Additionally, we fabricated a multi-walled carbon nanotube (MWCNT)/PDMS composite-based BDAP (c-BDAP), which exhibited high heat resistance and high electrical conductivity. The conductivity of c-BDAP was 6.16 × 10⁻³ S m⁻¹, and it had a weight loss of ∼4% at 300 °C after 1 h. Our findings can inspire the development of low-cost and high-performance c-BDAPs, which are reliable for various robot arm movements.