Development of a self-healing soft pneumatic actuator: a first concept

Area of Science:

• Robotics
• Materials Science
• Polymer Chemistry

Background:

• Soft pneumatic actuators (SPAs) offer safe interaction in unstructured environments due to their intrinsic softness and impact resistance.
• Existing SPAs are vulnerable to damage from sharp objects, limiting their durability in real-world applications.
• Self-healing (SH) mechanisms are needed to repair damage in soft actuator materials.

Purpose of the Study:

• To integrate a self-healing mechanism into soft pneumatic actuators (SPAs).
• To develop and evaluate SPAs constructed entirely from self-healing Diels-Alder (DA) polymers.
• To introduce a novel 'shaping through folding and self-healing' process for constructing SH-SPAs.

Main Methods:

• Diels-Alder (DA) polymers were synthesized and characterized for their mechanical and self-healing properties.
• A single-cell prototype (SH-SPC) was fabricated entirely from DA-polymers using a folding and sealing technique.
• The prototype's thermo-mechanical and self-healing capabilities were experimentally validated.

Main Results:

• The DA-polymers exhibited suitable mechanical and self-healing properties.
• The 'shaping through folding and self-healing' process enabled the creation of airtight 3D structures at low temperatures (<90 °C).
• The SH-SPC prototype demonstrated complete healing of macroscopic incisions at low temperatures (<70 °C).

Conclusions:

• Self-healing Diels-Alder polymers are feasible for constructing robust soft pneumatic actuators.
• The novel shaping process allows for efficient fabrication of self-healing actuator structures.
• This work presents the first SPA entirely made of self-healing polymers, paving the way for more durable soft robotic systems.