Design and evaluation of micro-sized glass bubble embedded PDMS composite for application to haptic forceps

The purpose of this study was to improve the durability and gripping performance of haptic forceps without damaging the counter materials. Glass bubbles (GBs) were embedded on the surface of polydimethylsiloxane (PDMS) to form a GB embedded PDMS (GBEP) composite, and then coated on the gripping part of the haptic forceps. The PDMS base and a curing agent were mixed with various precuring times, and the degree of embedding of GBs on the PDMS surface was controlled. As the precuring time increased, the depth of the GBs embedded in the PDMS surface decreased significantly. The friction coefficients of the GBEP specimens were lower than those of the bare PDMS. Bare PDMS and GBEP specimens with long precuring times were severely damaged, whereas GBEP specimens with short precuring times were relatively less damaged. When deionized (DI) water-based lubricants containing surfactants in various weight ratios were used, the friction coefficient of the specimens significantly decreased compared with dry or DI water lubrication conditions. Although the counter material was severely damaged by uncoated haptic forceps, it was not damaged by PDMS and GBEP coated haptic forceps, respectively. The durability of GBEP was superior to that of bare PDMS, and GBEP coated haptic forceps maintained gripping performance.