Soft robots manufactured out of self-healing polymers have the ability to repair macroscopic damage.

Healable soft robotic systems have been developed by constructing flexible membranes out of Diels?Alder (DA) polymer networks. In these components, relatively large amounts of damage, on the centimeter scale, can be healed, provided that the temperature is increased to 80?90 ?C. This article presents a new DA polymer network that can heal at room temperature through a smart design of the network that increases the molecular mobility in the material. This new material is used to develop the first healable soft robotic prototype that can autonomously recover from severe, realistic damage. The soft pneumatic hand can recover from various types of injuries, including being cut completely in half, without the need for a temperature increase. After healing, the performance of the soft robotic prototype is recovered.

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 appears during actuation. This paper proposes to develop soft pneumatic actuators out of multiple Diels–Alder polymers that can 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.