Featured Research

from universities, journals, and other organizations

Robots with lift: Researchers use combustible gases to power leaping machines

Date:
February 13, 2013
Source:
Harvard University
Summary:
Using small explosions produced by a mix of methane and oxygen, researchers have designed a soft robot that can leap as much as a foot in the air. That ability to jump could one day prove critical in allowing the robots to avoid obstacles during search and rescue operations following a disaster.

Combustible gases are powering leaping machines.
Credit: Image courtesy of Harvard University

They can already stand, walk, wriggle under obstacles, and change colors. Now researchers are adding a new skill to the soft robot arsenal: jumping.

Using small explosions produced by a mix of methane and oxygen, researchers at Harvard have designed a soft robot that can leap as much as a foot in the air. That ability to jump could one day prove critical in allowing the robots to avoid obstacles during search and rescue operations. The research is described in a Feb. 6 paper in the international edition of Angewandte Chemie.

"Initially, our soft robot systems used pneumatic pressure to actuate," said Robert Shepherd, first author of the paper, former postdoctoral researcher in the Whitesides Research Group at Harvard, and now an assistant professor at Cornell. "While that system worked, it was rather slow -- it took on the order of a second. Using combustion, however, allows us to actuate the robots very fast. We were able to measure the speed of the robot's jump at 4 meters per second."

Just as with other soft robots, the three-legged jumping system begins life as a mold created by a 3-D printer. The robots are molded using soft silicone that allows them to stretch and flex.

But where pneumatic robots are connected to tubing that pumps air, the jumping robots are connected to tubes that deliver a precisely controlled mix of methane and oxygen. Using high-voltage wires embedded in each leg of the robot, researchers deliver a spark to ignite the gases, causing a small explosion that sends the robot into the air.

Among the key design innovations that allowed the combustion system to work, Shepherd said, was the incorporation of a simple valve into each leg of the robot.

"We flow fuel and oxygen into the channels, and ignite it," Shepherd said. "The heat expands the gas, causing the flap to close, pressurizing the channel and causing it to actuate. As the gas cools, the flap opens and we push the exhaust out by flowing more gas in. So we don't need to use complex valve systems, all because we chose to mold a soft flap into the robot from the beginning."

While the notion of using combustion to power a soft robot was enticing, it also came with a number of critical questions, not the least of which was whether the soft silicone used to create the robots would even survive.

"It's a lot more powerful, but the question we had to answer was whether it was compatible -- were the temperatures compatible -- with this system," Shepherd said. "What we were able to show is, because the duration of the explosion is so short, the energies absorbed by the robot are small enough to be compatible with soft robots. What's more, the temperature of the robot increases by, on average, less than one kelvin."

While he hopes to see internal combustion systems developed that can allow robots to walk or even run, Shepherd said jumping made sense as a starting point.

"Because it releases so much energy so fast, it made sense for jumping to be the first 'gait' we explored with this system," he said. "The next step now is to learn how we can use this combustion system for other gaits, like running or even walking."

A challenge in those cases, beyond programming the robot limbs to work in the proper order, will be developing a system to store the energy produced during combustion for later release.

"Right now, we use that energy immediately," Shepherd said. "For walking, we may need to release that energy over a longer period of time."

Although the system described in the paper is limited by tethers -- tubes to deliver the combustible gases and wires to deliver the spark needed for ignition -- the Whitesides group is working on one day freeing the robots from such limits.

"There's nothing wrong with having tethered robots -- many systems used in industry are tethered," Shepherd said. "For some search and rescue applications, however, having an untethered robot will be necessary."

"When we do develop those systems, it would be useful to have a power source that can deliver a high volumetric energy density for a long time, and burning hydrocarbon fuels is a proven way to do that," he continued. "One of our goals for this paper was to show that we can use those fuels in soft systems, and I believe we've done that."

Other authors on the paper are Adam Stokes, Jacob Freake, Phillip Snyder, Aaron Mazzeo, Ludovico Cademartiri, Stephen A. Morin, George M. Whitesides, the Woodford L. and Ann A. Flowers University Professor at Harvard, and Jabulani Barber, an FAS research associate with the Whitesides Research Group.

Video at: http://news.harvard.edu/gazette/story/2013/02/robots-with-lift/


Story Source:

The above story is based on materials provided by Harvard University. The original article was written by Peter Reuell. Note: Materials may be edited for content and length.


Journal Reference:

  1. Robert F. Shepherd, Adam A. Stokes, Jacob Freake, Jabulani Barber, Phillip W. Snyder, Aaron D. Mazzeo, Ludovico Cademartiri, Stephen A. Morin, George M. Whitesides. Using Explosions to Power a Soft Robot. Angewandte Chemie International Edition, 2013; DOI: 10.1002/anie.201209540

Cite This Page:

Harvard University. "Robots with lift: Researchers use combustible gases to power leaping machines." ScienceDaily. ScienceDaily, 13 February 2013. <www.sciencedaily.com/releases/2013/02/130213152418.htm>.
Harvard University. (2013, February 13). Robots with lift: Researchers use combustible gases to power leaping machines. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2013/02/130213152418.htm
Harvard University. "Robots with lift: Researchers use combustible gases to power leaping machines." ScienceDaily. www.sciencedaily.com/releases/2013/02/130213152418.htm (accessed April 16, 2014).

Share This



More Computers & Math News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Google Patents Contact Lens Cameras; Internet Is Wary

Google Patents Contact Lens Cameras; Internet Is Wary

Newsy (Apr. 15, 2014) — Google has filed for a patent to develop contact lenses capable of taking photos. The company describes possible benefits to blind people. Video provided by Newsy
Powered by NewsLook.com
The Walking, Talking Oil-Drigging Rig

The Walking, Talking Oil-Drigging Rig

Reuters - Business Video Online (Apr. 15, 2014) — Pennsylvania-based Schramm is incorporating modern technology in its next generation oil-drigging rigs, making them smaller, safer and smarter. Ernest Scheyder reports. Video provided by Reuters
Powered by NewsLook.com
NSA Leaks Net Pulitzer For Guardian, Washington Post

NSA Leaks Net Pulitzer For Guardian, Washington Post

Newsy (Apr. 14, 2014) — The Pulitzer Prize for Public Service was awarded to The Washington Post and The Guardian for their work covering the NSA's surveillance programs. Video provided by Newsy
Powered by NewsLook.com
Google Buys Drone Maker, Hopes to Connect Rural World

Google Buys Drone Maker, Hopes to Connect Rural World

Newsy (Apr. 14, 2014) — Formerly courted by Facebook, Titan Aerospace will become a part of Google's quest to blanket the world in Internet connectivity. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins