Conceptual exploration of a gravity-assisted electrorheological fluid-based gripping methodology for assistive technology

Gripping devices help patients carry out everyday tasks and increase their independence. However, there seems to be a lack of bionic gripping technologies that can fully adapt to any possible shape, as the use of artificial fingers and predetermined grip settings limits the operating space. The development of a more agile device, which is operated by a simple control paradigm, could greatly benefit users. An electrorheological (ER) fluid system should be able to adapt to the shape of an object and then hold that configuration. The aim of this study was to explore if a conceptual prototype of an ER system could hold a geometric shape when it is activated. A test rig was constructed with a moving part (set in different silicone oils) that could be displaced using a tensometer. Silica particles were dispersed in the silicone oils, and a field with a voltage of 4 kV mm−1 was generated to activate the fluid. The results show that the developed system can support an increased force when activated and hold a simple geometric position without any noticeable delay. This outcome provides an initial proof of concept for a possible new (gravity-assisted) gripping approach using smart fluids, which could be developed with materials that are biocompatible and widely available.