Looking at the new wave of soft robotics
Lu Rahman looks at the new wave of robotics. Soft and pliable these new devices take their inspiration from nature offering great potential for healthcare. Are we about to witness a new group of very useful and compliant, flexible friends?
Mention robots and chances are most people conjure up Dr Who-style Cybermen or the automated machines like the ones we see in today’s car manufacturing plants. These hard-framed, human-like devices are a familiar sight using their metal limbs to imitate arms, or carry out repetitive tasks at both speed and with great accuracy.
But there’s a new wave of robots making their way into our imaginations and our lives. Soft and squishy and stretchy, these devices take a lead from nature while boasting the ability to squeeze and move in a more flexible and compliant manner. And the healthcare world is casting its eye on these flexible structures made of elastomeric material.
Soft robotics offer a new generation of technology – compliant, flexible material that mimics natural tissue and can be used to interact with humans. Powered by ‘artificial muscle’ these devices are the new frontier of automation and in the healthcare sector opportunities for this technology are immense and exciting – we’re hearing more and more about its potential life-changing applications.
Last year Nature magazine reported on the work being carried out at the Sant'Anna School of Advanced Studies in Italy where Cecilia Laschi and her team studied the movements of an octopus and how it handled food – the idea behind this was to create a robot that could mimic those movements – twisting and shaping and wrapping, free from the rigours of computer programming and inflexible hard bodies.
In the UK SoftLab Bristol, at the University of Bristol, is carrying out major research on soft robotics. Projects include artificial muscles using soft electro-active and chemo-active actuators, artificial stomachs and soft sensors.
At the National Science Foundation (NSF) in Virginia, US, work has been done looking at the way polymer-based materials can be turned into artificial muscles. It’s thought that these novel robotic devices offer a range of benefits over conventional robots. Due to their flexibility, they could offer hope in a variety of healthcare situations, acting as replacement muscles for disabled people, for example.
The role of polymer
With his team, Kwang Kim, University of Nevada and the NSF has been researching the development of artificial muscles using polymer-based material. Last year the NSF revealed that getting the material right is one of the biggest challenges. Kim’s team was using an ionic polymer-metal composite – the electroactive nature of the polymer allows electricity to be run through it so that the shape can changed – this of course is markedly different to conventional robots which require motors to move.
The robotic market is strong and offers great potential. According to Crystal Market Research, the value of the healthcare assistive robots sector is set to hit $1 billion by 2025. If the soft robotic develops there’s every chance it could have a significant slice of the financial pie.
Soft hearted?
Earlier this year Harvard University and Boston Children’s Hospital revealed some exciting work involving a customisable soft robot that fits around a heart to help it beat. The research has huge implications for anyone who has suffered heart failure.
According to Harvard, the soft robotic sleeve, “twists and compresses in synch with a beating heart, augmenting cardiovascular functions weakened by heart failure. Unlike currently available devices that assist heart function, Harvard’s soft robotic sleeve does not directly contact blood. This reduces the risk of clotting and eliminates the need for a patient to take potentially dangerous blood thinner medications. The device may one day be able to bridge a patient to transplant or to aid in cardiac rehabilitation and recovery.”
The device is attached to a pump that uses air to power soft actuators. Each sleeve can be customised for each patient and according to for example, the side of their heart where more power is needed.
Ellen Roche, the paper’s first author and former PhD student at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and The Wyss Institute of Biologically Inspired Engineering at Harvard University commented: “This research demonstrates that the growing field of soft robotics can be applied to clinical needs and potentially reduce the burden of heart disease and improve the quality of life for patients.”
“This work represents an exciting proof of concept result for this soft robot, demonstrating that it can safely interact with soft tissue and lead to improvements in cardiac function. We envision many other future applications where such devices can deliver mechanotherapy both inside and outside of the body,” said Conor Walsh, senior author of the paper and the John L Loeb Associate Professor of Engineering and Applied Sciences at SEAS and Core Faculty Member at the Wyss Institute.
Soft wearable robots
Not quite mimicking artificial muscle but none the less highly exciting for the future of healthcare, are soft wearable robots which combine the latest in textile science with robotics.
Recently the Wyss Institute for Biologically Inspired Engineering at Harvard University collaborated with ReWalk Robotics to develop wearable exosuits for patients with limited walking ability.
"This is a very exciting for soft exosuit technology," said Conor Walsh, John L Loeb associate professor of Engineering and Applied Sciences at Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), founder of the Harvard Biodesign Lab and a core faculty member at the Wyss Institute for Biologically Inspired Engineering.
The exosuit - a soft wearable robot - was developed at the Wyss Institute by Walsh and his team through prototyping that included the involvement of roboticists, mechanical and biomechanical engineers, apparel designers and software engineers.
Using form-fitting, fabric-based designs that are lightweight and non-restrictive, the Wyss Institute's soft exosuit uses compact, powerful actuators packaged in a belt to provide assistance to the wearer's legs in a physiologically relevant manner.
These enhanced movements have the potential to assist wearers in walking with greater stability and metabolic efficiency, which could prevent injury and reduce fatigue, the Institute said.
Over the course of its development, the soft exosuit has been the catalyst for entirely new forms of functional textiles, flexible power systems and control strategies that integrate the suit and its wearer in ways that mimic the natural biomechanics of the human musculoskeletal system, according to the Institute.
Larry Jasinski, CEO of ReWalk, said: "There is a great need in the health care system for lightweight, lower-cost wearable exoskeleton designs to support stroke patients, individuals diagnosed with multiple sclerosis and senior citizens who require mechanical mobility assistance.”
Walsh scooped Rolex Award last year for his work. Given that globally 15 million people suffer a stroke each year, the product has huge potential.
Soft and stretchy sensors
It’s not only robotics that are becoming increasingly flexible. And the Wyss Institute is once again behind a breakthrough. Wearable technologies have exploded into both healthcare and consumer markets. Recognising that most of the electronic sensors used in these devices are made from hard, inflexible materials, a team of researchers at the Wyss has created a highly sensitive soft capacitive sensor made of silicone and fabric that moves and flexes with the human body to unobtrusively and accurately detect movement.
"We're really excited about this sensor because, by leveraging textiles in its construction, it is inherently suitable for integration with fabric to make 'smart' robotic apparel," says Walsh.
"Additionally, we have designed a unique batch-manufacturing process that allows us to create custom-shaped sensors that share uniform properties, making it possible to quickly fabricate them for a given application," says Ozgur Atalay, postdoctoral fellow at the Wyss Institute.
This research is published in Advanced Materials Technologies, and the protocol is available as part of the Harvard Biodesign Lab's Soft Robotics Toolkit.
Soft robotics offer great potential for our health and wellbeing. Free from the metal clad structures of conventional robots, these flexible designs herald a new future for healthcare and medical device pioneers seeking to push the boundaries in design. As Laschi commented in Nature magazine, “It’s a completely different way of building robots.”