In new generation soft robots the actuation performance can be increased by using multiple materials in the actuator designs. However, the lifetime of these actuators is often limited due to failure that occurs at the weak multi-material interfaces that rely almost entirely on physical interactions and where stress concentration appear during actuation. This paper proposes to develop soft pneumatic actuators out of multiple Diels-Alder polymers that have the ability to generate strong covalent bonds at the multi-material interface by means of a heat-cool cycle. Through tensile testing it is proven that high interfacial strength can be obtained between two merged Diels-Alder polymers. This merging principle is exploited in the manufacturing of multi-material bending soft pneumatic actuators in which interfaces are no longer the weakest links. The applicability of the actuators is illustrated by their operation in a soft hand and a soft gripper demonstrator. In addition, the use of Diels-Alder polymers incorporates healability in bending actuators. It is experimentally illustrated that full recovery of severe damage can be obtained by subjecting the multi-material actuators to a healing cycle.
Original languageEnglish
Pages (from-to)34-51
Number of pages17
JournalActuators
Volume9
Issue number2
Publication statusPublished - 30 Apr 2020

ID: 51697124