ON-OFF Adhesive Grippers for Earth-Orbit

Abstract

This paper presents the development of a tool for grappling non-cooperative objects such as orbital debris and defunct or malfunctioning satellites. Using gecko-like adhesives, which can be turned ON and OFF and reused many times, the tool grapples objects by virtually any surface, significantly reducing the requirements on other systems like perception, GN&C, and control during the grapple sequence. Preliminary development is complete, including testing the adhesive on over 30 spacecraft surfaces, testing to over 30,000 ON-OFF cycles and to over 1 year of continuous hold, and testing in a thermalvacuum chamber at full vacuum and down to -60C (future tests should extend this down to -120C). Several iterations of the grappling tool have been designed, prototyped, and tested. A scalable design that uses many sets of opposed pads was validated grappling a representative piece of debris (33kg) in a rolling test on a flat floor with relative translational rates from 0 to 2 m/s and relative spin rates from 0 to 75 deg/s. Similar testing is currently underway on an air bearing flat floor.

Superior Low‐Temperature Reversible Adhesion Based on Bio‐Inspired Microfibrillar Adhesives Fabricated by Phenyl Containing Polydimethylsiloxane Elastomers

“…As a result, reduced compliance as well as reversible adhesion on natural surfaces thus might be resulted. Although several studies have taken into account the influence of temperature on microfibrillar adhesives for space applications, [ 23 ] the low‐temperature effect have not been comprehensively studied before.…”

A robotic device using gecko-inspired adhesives can grasp and manipulate large objects in microgravity

“…This capability allows robots to perform inspection and repair tasks, thereby protecting humans from dangerous extravehicular exposure (7). A climbing robot can reach more locations and is potentially more versatile than a robotic arm and camera (8,9). The robot needs to grip structures firmly and manipulate its body to perform desired tasks, some of which may require exerting substantial forces on the structure.…”

Gecko-Like Dry Adhesive Surfaces and Their Applications: A Review

“…As a Fig. 9 The robot grippers based on the different gecko-like dry adhesive surfaces: a the three-legged gripper for adhering the smaller scale silicon wafers [81]; b the three-legged grippers based on tendon transmission for adhering larger scale planar targets [145]; c the gripper based on parallel constant force springs for adhering large space floating targets [153]; d the gripper based on differential pulleys for adhering large space floating targets [154]; e the robot gripper that integrates both two pairs of opposed curved surface adhesive unit based on tangential adhesion and eight pairs of opposed planar adhesive unit based on normal adhesion [160]; f GeckoGripper [148]; g inflatable soft gripper with a deformable support cavity [150]; h-j the grippers based on tangential adhesion [156,157,159]; k the traditional pneumatic-driven soft robot gripper integrating the geckolike dry adhesive surface [166]; l the tendon-driven soft robot gripper integrating the gecko-like controllable adhesive surface [167]; m the parallel jaw gripper integrating a pair of wedge-shaped microstructure arrays arranged in the diagonal chevron pattern [168]; n the landing leg for assisting the aircraft to landing [164]; o the geckolike adhesive gripper for assisting the free-flying robot of Astrobee to complete temporary landing and grasping operations in the International Space Station [165] result, the gripper can evenly distribute the adhesive load on the adhesive interface through the negative pressure difference, and obtain the improved adhesive strength without sacrificing the flexibility (as shown in Fig. 9g) [150].…”

“…In the design based on parallel constant force springs (as shown in Fig. 9c), the loading tendons of each pair of opposed adhesive units are respectively connected to the constant force springs, so each adhesive unit undergoes loading independently during the loading process, and finally has approximately the same limit adhesion which is determined by the constant force spring [153]. In the design based on differential pulleys (as shown in Fig.…”