Integrated compliant actuation for untethered soft robotic systems

The use of soft, flexible technologies in robotic systems is a fundamental shift from the traditional basis of how a robot should be designed. Compliant, deformable materials allow many biological principles to be emulated and this emerging soft approach can create robots that robustly deal with uncertainty, interact more safely with humans and compliantly move through unstructured environments. However, the lack of soft, embedded actuators that reliably replicate the functionality of muscles in the animal body has become a technological bottleneck. This has limited how effectively soft robots can be applied outside of laboratory conditions in applications that require either autonomy from tethering to hard supply systems.

This project aims to develop innovative hybrid actuation systems which will expand the application of soft robotics towards autonomous and untethered systems. Like biological muscle, these actuators will be fully integrated into soft robotic devices without sacrificing their performance. The proposed developments of improved soft actuation performance are driven by two underlying objectives. The first of these relates to how the power to weight ratio (W/kg) of soft actuators can be sufficiently increased so that they are comparable to rigid actuators. The second overarching objective is driven by the need to untether soft robots from hard supply systems such as valves, pumps and electric motors. The motivations for these objectives are to give soft robotic systems autonomy, mobility and, ultimately, inherent compliance of all sub-systems.

In this project advances will be made with two classes of soft robotic technology, fluidic actuators and thermo-active actuators, which will each be integrated with additional technologies such as electro-active polymers and evaporator-condenser networks. These new hybrid actuators will form hierarchical structures that do not need any rigid components and can be fully deformed. By addressing the need for soft robotic technologies that can be untethered and mobile the project will, if successful, have significant impact in the development of autonomous soft robots and wearable soft robotic healthcare technologies.

The success of this proposal will enable soft robotic devices to be untethered from constraining rigid components, which will greatly improve their capacity for human robot interaction and, in particular, assistive and wearable robotic technologies. This branch of healthcare technologies includes assistive devices for the elderly and infirm such as rehabilitation from stroke, as well as prosthetics. These are highly relevant technologies as the UK faces the challenges of an ageing population and severely strained healthcare resources. The project outcomes will help bring these emerging technologies towards application by giving the actuation systems much needed mobility and power density to improve human robot interaction and reduce the device weight.

It has been reported that technologies related to Robotics and Autonomous Systems will have a potential annual economic impact in 2025 between $9.8-19.3 trillion. This project seeks to contribute to UK's strength in robotics by advancing soft robotic technologies which are at the forefront of this field.

This project will give a Research Assistant (RA) training and allow them to gain experience in developing novel technologies with a range of development and experimentation techniques. The outcomes of this project will inform the teaching of undergraduate and postgraduate students to help give them relevant, leading edge skills for careers as innovative robotics engineers.