Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Design tool beefs up artificial muscles

05.07.2016

Polymeric materials that stretch out when electrically stimulated can benefit from realistic numerical simulations.

Robotic devices are usually composed of hard components such as aluminum and steel, in contrast to the soft tissues that power biological organisms. A study conducted by A*STAR researchers now makes it easier to turn squishy, electroactive polymers into artificial muscles and biomimetic energy harvesters through computer-aided design [1].


A finite element simulation of a viscoelastic dielectric elastomer actuator, which undergoes wrinkling under voltage. © 2016 A*STAR Institute of High Performance Computing

Dielectric elastomers are rubbery, insulating membranes that respond dramatically to electric fields — when sandwiched between two electrodes, they can expand by several hundred per cent in a two-dimensional plane. These special deformation properties have led to applications such as soft-body robotics and sensors. However, the shape-shifting membranes often develop changes in their electrically stimulated response over time, making them hard to optimize for long-term use.

Keith Choon Chiang Foo from the A*STAR Institute of High Performance Computing and his team realized that numerical simulations could help to improve dielectric elastomer devices. They turned to finite element analysis, a tool that predicts the performance of complex objects by modeling them as small interconnected geometric units, to reach this goal. But finding algorithms that replicate smart polymer behavior is not straightforward.

“Existing finite element software doesn’t have the capability to simulate soft rubbery materials that respond to electricity and involve large deformations,” says Foo. “Plus, most simulations of these polymers have been done using ‘in-house’ software, meaning source codes are not available to the scientific community.”

The researchers solved these issues with a model that revealed how repeated movements affected the membrane’s ability to respond to electricity and mechanical forces over time. Their algorithms coupled this property, known as viscoelasticity, to electrostatic charges in the device. They implemented this model into commercial finite element software. “We have made the subroutine freely available to aid other researchers,” adds Foo.

The team’s simulations highlighted examples where viscoelasticity has an impact on the performance of artificial muscle-like devices. For example, when an electrical pulse causes the membrane to stretch out, the elastomer takes a characteristic time to relax to the new configuration. If the pulse cycles at a rate close to this relaxation time, mechanical actuation can be significantly affected.

Further tests showed the improved finite element analysis could quantify the critical time delay between the instant an electrical signal is applied and the maximum polymer actuation achieved. Because the computations agree well with previous experimental data, Foo is confident this technique can reduce trial-and-error approaches to biomimetic devices.

“This simulation tool may prove very capable,” he remarks. “When we work with experimentalists, it helps guide our approach to soft machines.”

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing. For more information about the team’s research, please visit the Soft Matter Group webpage.

Reference

[1] Foo, C. C. & Zhang, Z.-Q. A finite element method for inhomogeneous deformation of viscoelastic dielectric elastomers. International Journal of Applied Mechanics 7, 1550069 (2015).

Associated links

A*STAR Research | Research SEA
Further information:
http://www.researchsea.com

More articles from Materials Sciences:

nachricht Barely scratching the surface: A new way to make robust membranes
13.12.2018 | DOE/Argonne National Laboratory

nachricht Topological material switched off and on for the first time
11.12.2018 | ARC Centre of Excellence in Future Low-Energy Electronics Technologies

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

UNLV study unlocks clues to how planets form

13.12.2018 | Physics and Astronomy

Live from the ocean research vessel Atlantis

13.12.2018 | Earth Sciences

Stanford researcher deciphers flows that help bacteria feed and organize biofilms

13.12.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>