Development of a Particle Mechanical Constraint of Variable Stiffness with Application to a Wearable Force Display

Abstract

This paper describes a new mechanical element that varies its stiffness to internal air pressure. The element, named Particle Mechanical Constraint (PMC), is a soft vinyl tube embedded with Styrofoam beads. Its shape varies freely with compression, elongation, bending and twisting. By exhausting the inside air, the PMC solidifies in an arbitrary shape and constrains all degrees-of-freedom. Stiffness and viscosity are adjustable via the inside air pressure. The PMC is light and safe, and therefore can be used as a wearable device. The application of a PMC to a wearable haptic display is described in this paper.