Rollable Multisegment Dielectric Elastomer Minimum Energy Structures for a Deployable Microsatellite Gripper

Abstract

Abstract-Debris in space present an ever-increasing problem for spacecraft in Earth orbit. As a step in the mitigation of this issue, the CleanSpace One (CSO) microsatellite has been proposed. Its mission is to perform active debris removal of a decommissioned nanosatellite (the CubeSat SwissCube). An important aspect of this project is the development of the gripper system that will entrap the capture target. We present the development of roll-able dielectric elastomer minimum energy structures (DEMES) as the main component of CSO's deployable gripper. DEMES consist of a prestretched dielectric elastomer actuator membrane bonded to a flexible frame. The actuator finds equilibrium in bending when the prestretch is released and the bending angle can be changed by the application of a voltage bias. The inherent flexibility and lightweight nature of the DEMES enables the gripper to be stored in a rolled-up state prior to deployment. We fabricated proof of concept actuators of three different geometries using a robust and repeatable fabrication methodology. The resulting actuators were mechanically resilient to external deformation, and display conformability to objects of varying shapes and sizes. Actuator mass is less than 0.65 g and all the actuators presented survived the rolling-up and subsequent deployment process. Our devices demonstrate a maximum change of bending angle of more than 60 degrees and a maximum gripping (reaction) force of 2.2 mN for a single actuator.Index Terms-Active debris removal (ADR), artificial muscles, deployable mechanism, dielectric elastomer actuator (DEA), space debris.

Versatile Soft Grippers with Intrinsic Electroadhesion Based on Multifunctional Polymer Actuators

“…The electroadhesion force also enables the picking up of flat and deformable objects. The gripper can be controlled only by a single control voltage thanks to the simple, compliant composite structure, similar in overall concept to [15,[19][20][21][22][23][24] . These features lead to a highlyintegrated, multifunctional conformal soft gripper with fast motion (~100 ms to close fingers), high holding force and simplified structure and control, paving a way for sensitive, highly versatile grippers for soft robotics.…”

Printing low-voltage dielectric elastomer actuators

“…Actuation strains greater than 100% (Ref. 1) and sub-ms response time 2 can be achieved with DEAs, which find applications in a wide range of fields including soft-robotics, [3][4][5] optics, 2,6,7 and microfluidics. [8][9][10] DEAs are well suited to miniaturisation, as power density is high, 1 and complex shapes and systems can be made using simple architectures.…”

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

“…Other applications that have been produced with the present process (or slight variations thereof) include deformable cell culture systems 14 , Dielectric elastomer generators 15 , multi-segment soft grippers 16 , or tunable mm-wave radio frequency phase shifters …”