A breakthrough for soft robots to advance artificial muscles
Source: Vito Cacucciolo / 2019 EPFL 2019 EPFL

A breakthrough for soft robots to advance artificial muscles

Scientists have developed a tiny pump that could play a big role in the development of autonomous soft robots, lightweight exoskeletons and smart clothing. Flexible, silent and weighing only one gram, it is poised to replace the rigid, noisy and bulky pumps currently used.

Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments. Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines’ moving parts. Because they are connected to these bulky pumps by tubes, these robots have limited autonomy and are cumbersome to wear at best.

A breakthrough for soft robots to advance artificial muscles
Source: Vito Cacucciolo / 2019 EPFL 2019 EPFL

Cutting soft robots’ tether

Researchers in EPFL’s Soft Transducers Laboratory (LMTS) and Laboratory of Intelligent Systems (LIS), in collaboration with researchers at the Shibaura Institute of Technology in Tokyo, Japan, have developed the first entirely soft pump – even the electrodes are flexible. Weighing just one gram, the pump is completely silent and consumes very little power, which it gets from a 2 cm by 2 cm circuit that includes a rechargeable battery. “If we want to actuate larger robots, we connect several pumps together,” says Herbert Shea, the director of the LMTS at the School of Engineering.

This innovative pump could rid soft robots of their tethers. “We consider this a paradigm shift in the field of soft robotics,” adds Shea. Soft pumps can also be used to circulate liquids in thin flexible tubes embedded in smart clothing, leading to garments that can actively cool or heat different regions of the body. That would meet the needs of surgeons, athletes and pilots, for example.

A breakthrough for soft robots to advance artificial muscles
Source: Marc Delachaux / 2019 EPFL

How does it work?

The soft and stretchable pump is based on the physical mechanism used today to circulate the cooling liquid in systems like supercomputers. The pump has a tube-shaped channel, 1 mm in diameter, inside of which rows of electrodes are printed. The pump is filled with a dielectric liquid. When a voltage is applied, electrons jump from the electrodes to the liquid, giving some of the molecules an electrical charge. These molecules are subsequently attracted to other electrodes, pulling along the rest of the fluid through the tube with them. “We can speed up the flow by adjusting the electric field, yet it remains completely silent,” says Vito Cacucciolo, a post-doc at the LMTS and the lead author of the study.

A breakthrough for soft robots to advance artificial muscles
Source: Vito Cacucciolo / 2019 EPFL 2019 EPFL

Developing artificial muscles

The researchers have successfully implanted their pump in a type of robotic finger widely used in soft robotics labs. They are now collaborating with Koichi Suzumori’s laboratory in Japan, which is developing fluid-driven artificial muscles and flexible exoskeletons.

The EPFL team has also fitted a fabric glove with tubes and shown that it is possible to heat or cool regions of the glove as desired using the pump. “It works a little like your home heating and cooling system” says Cacucciolo. This application has already sparked interest from a number of companies.

Subscribe to our newsletter

Related articles

Ultra-thin sensitive strain sensors

Ultra-thin sensitive strain sensors

Researchers have developed a new range of nanomaterial strain sensors that are 10 times more sensitive when measuring minute movements, compared to existing technology.

Stroke patients: robotic arm aids in rehabilitation

Stroke patients: robotic arm aids in rehabilitation

The Hong Kong Polytechnic University (PolyU) recently developed a robotic arm to facilitate self-help and upper-limb mobile rehabilitation for stroke patients.

Exoskeleton training expands options for stroke rehab

Exoskeleton training expands options for stroke rehab

Researchers have demonstrated that high-dose therapy gait training using robotic exoskeletons may aid early rehabilitation for acute stroke.

Exoskeleton and brain-machine interface boost stroke rehab

Exoskeleton and brain-machine interface boost stroke rehab

Researchers have developed a system that combines a brain-computer interface and a robotic arm that responds to the actual intentions of treated patients.

Brain injury: Exoskeleton training improves walking

Brain injury: Exoskeleton training improves walking

Researchers have shown that gait training using robotic exoskeletons improved motor function in adolescents and young adults with acquired brain injury.

Handheld exoskeleton improves hand mobility problems

Handheld exoskeleton improves hand mobility problems

Researchers have developed a robotic exoskeleton that improves the lives of people with limited or no ability to move due to neurological and/or physiological disorders.

Sarcopenia: Robotic muscles could turn back body clock

Sarcopenia: Robotic muscles could turn back body clock

Loss of strength and muscle wastage is currently an unavoidable part of getting older and has a significant impact on health and quality of life.

Robotics for everyone or only for the average person?

Robotics for everyone or only for the average person?

Exoskeletons are one technology with great potential - but is often developed for average people. So what about people who are small and thin, or tall and overweight?

Exosuit makes stroke survivors walk farther

Exosuit makes stroke survivors walk farther

Research study in stroke survivors with chronic hemiparesis shows soft exosuit technology to bring immediate improvements in walking speed and endurance tests.

Popular articles

Subscribe to Newsletter