UCLA

Bistable electroactive polymer (BSEP) exhibiting large-strain actuation, shape memory effect, sharp and reversible rigid-to-rubbery transition, and rigid-to-rigid deformation is regarded as a competitive candidate for refreshable Braille display. Two new BSEP materials with a long-chain urethane diacrylate and stearyl acrylate named BS80-1 and BS80-2, respectively, were studied for their mechanical properties and actuation performances. BS80-2, compared with BS80-1, presents a better bonding with electrodes made of carbon nanotubes, a better toughness up to 312% strain, a reinforced tensile strength and a larger elongation at break compared to BS80-1. On the other hand, to better understand the actuation performance of both materials, computer simulation under same experimental conditions using finite element analysis was also conducted. Through combining the experimental and simulated actuation performance, data we obtained could be employed as guidance to fabrication of the Braille cell. Unlike conventional high electric filed induced actuation of BSEP, for our refreshable Braille display, air pressure is utilized to trigger the actuation. In this way, the voltage needed to drive the device could be significantly lower and the safety of device could be improved as well.