Near-Zero Poisson’s Ratio and Large-Area Metamaterial Made of UV-PDMS Using 3D Backside Exposure

This paper proposes a processing method for UV-PDMS, a UV-curable silicone rubber required for flexible polymer MEMS. Three-dimensional (3D) backside exposure method for structure fabrication using flow of liquid UV-PDMS flow improved the relative dimensional error from 40% to 12.5% compared with the vertical backside exposure. In addition, large-area specimens were fabricated by joining two-dimensional mechanical metamaterial structures with UV-PDMS, and their elongation and Poisson's ratio were evaluated by uniaxial tensile testing. The flexible structure of the metamaterial produced a design that has a Poisson's ratio of nearly zero.