Schematic of an assembled soft dynamic DEA valve.
An assembled soft dynamic DEA valve.
Source: Siyi Xu/Harvard SEAS

Components for the next generation of soft robotics

Scientists at Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a soft that valve paves the way for fully soft robots.

Soft robots driven by pressurized fluids could explore new frontiers and interact with delicate objects in ways that traditional rigid robots can't. But building entirely soft robots remains a challenge because many of the components required to power these devices are, themselves, rigid.

Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed electrically-driven soft valves to control hydraulic soft actuators. These valves could be used in assistive and therapeutic devices, bio-inspired soft robots, soft grippers, surgical robots, and more.

"Today's rigid regulation systems considerably limit the adaptability and mobility of fluid-driven soft robots," said Robert J. Wood, the Harry Lewis and Marlyn McGrath Professor of Engineering and Applied Sciences at SEAS. "Here, we have developed soft and lightweight valves to control soft hydraulic actuators that open up possibilities for soft on-board controls for future fluidic soft robots."

Soft valves aren't new but so far none have achieved the pressure or flow rates required by many existing hydraulic actuators. To overcome those limitations, the team developed new electrically powered dynamic dielectric elastomer actuators (DEAs). These soft actuators have ultra-high power density, are lightweight, and can run for hundreds of thousands of cycles. The team combined these new dielectric elastomer actuators with a soft channel, resulting in a soft valve for fluidic control.

"These soft valves have a fast response time and are able to control fluidic pressure and flow rates that match the needs of hydraulic actuators," said Siyi Xu, a graduate student at SEAS and first author of the paper. "These valves give us fast, powerful control of macro-and small-scale hydraulic actuators with internal volume ranging from hundreds of microliters to tens of milliliters."

Using the DEA soft valves, the researchers demonstrated control of hydraulic actuators of different volumes and achieved independent control of multiple actuators powered by a single pressure source. "This compact and light-weight DEA valve is capable of unprecedented electrical control of hydraulic actuators, showing the potential for future on-board motion control of soft fluid-driven robots," said Xu.

The research was published in the Proceedings of the National Academy of Sciences (PNAS).

Subscribe to our newsletter

Related articles

Smart elastomers make robots more touchy-feely

Smart elastomers make robots more touchy-feely

A new generation of robotic tools are beginning to be realized thanks to a combination of strong 'muscles' and sensitive 'nerves' created from smart polymeric materials.

How soft robots can turn rigid on demand

How soft robots can turn rigid on demand

Researchers have developed a new type of control system that may broaden robots’ range of tasks and allow safer interactions with people.

New material could help robots flex their muscles

New material could help robots flex their muscles

Researchers have developed a shape memory polymer that stores almost six times more energy than previous versions.

Sensor material powers wearables in extreme cold

Sensor material powers wearables in extreme cold

A new material that combines the flexibility of human skin with improved conductivity and tolerance of temperatures as low as -93 C.

Simulator helps robots sharpen their cutting skills

Simulator helps robots sharpen their cutting skills

A simulation engine predicts the forces acting on a knife as it cuts through soft materials, a capability that could have applications for safer surgical robotics.

Universal approach to tailoring soft robots

Universal approach to tailoring soft robots

An integrated design optimisation and fabrication workflow opens new opportunities for tailoring the mechanical properties of soft machines.

Shape-changing implants to treat severe pain

Shape-changing implants to treat severe pain

An ultra-thin, inflatable device that uses a combination of soft robotic fabrication techniques and microfluidics can be used to treat the most severe forms of pain without the need for invasive surgery.

A Lego system for building robots

A Lego system for building robots

Scientists have developed a system with which they can fabricate miniature robots building block by building block, which function exactly as required.

A conductive hydrogel for medical applications

A conductive hydrogel for medical applications

Researchers have developed a method to produce graphene-enhanced hydrogels with an excellent level of electrical conductivity.

Popular articles

Subscribe to Newsletter