Robot fish could monitor water quality

November 02, 2009

EAST LANSING, Mich. -- Nature inspires technology for an engineer and an ecologist teamed up at Michigan State University. They're developing robots that use advanced materials to swim like fish to probe underwater environments.

"Fish are very efficient," explained Xiaobo Tan, an assistant professor of electrical and computer engineering. "They can perform very efficient locomotion and maneuvering in the water."

Robotic fish - perhaps schools of them operating autonomously for months - could give researchers far more precise data on aquatic conditions, deepening our knowledge of critical water supplies and habitats.

Tan and Elena Litchman, an assistant professor of zoology based at MSU's Kellogg Biological Station on Gull Lake in Kalamazoo County, recently won funding from the National Science Foundation to integrate their research.

"The robotic fish will be providing a consistent level of data that hasn't been possible before," Litchman explained. "With these patrolling fish we will be able to obtain information at an unprecedentedly high spatial and temporal resolution. Such data are essential for researchers to have a more complete picture of what is happening under the surface as climate change and other outside forces disrupt the freshwater ecosystems. It will bring environmental monitoring to a whole new level."

The robotic fish will carry sensors recording such things as temperature, dissolved oxygen, pollutants and harmful algae. Tan also is developing electronics so the devices can navigate and communicate in their watery environment.

"This project will greatly advance bio-robotic technology," Tan said. "The project is very practical and we are designing the fish to be inexpensive so they can be used in various applications like sampling lakes, monitoring aquafarms and safeguarding water reservoirs."

The robotic fish might detect toxic algal blooms, for example.

"As air temperature increases, the lakes and reservoirs also heat up," Litchman said. "Increasing water temperature creates strong stratification within the various layers of the water and this may lead to increased growth of harmful algae. Some of these algal blooms create poor conditions for fish and exude toxins that also endanger people."

To mimic how fish swim and maneuver, Tan builds "fins" for robotic fish with electro-active polymers that use electricity to change shape. Similar to real muscle tissue, ion movements twist and bend the polymer when voltage is applied. The effect works in reverse, too - slender "feelers" could signal maneuvering circuits in a sort of electro-active central nervous system. Infrared sensors also could be used for "eyes" to avoid obstacles.

The robots will communicate wirelessly with a docking station after surfacing at programmed intervals and could similarly be linked to other robotic fish for coordinated maneuvers or signal relay. Global positioning system technology and inertial measurement units will allow precise navigation.

It's not big, but it's a keeper: A 9-inch prototype now swimming in Tan's laboratory tank is modeled on the yellow perch by John Thon, a member of the research team who teaches art at nearby Holt Junior High School. The device isn't strong enough to resist stiff currents, so for now must be confined to relatively still waters. Future versions will incorporate the ability to change buoyancy to assist locomotion and maneuver.
-end-
Tan's earlier foundational work on the robots was funded by the Office of Naval Research and a CAREER award from the National Science Foundation. Litchman's work on algal blooms also is supported by an NSF CAREER grant.Michigan State University has been advancing knowledge and transforming lives through innovative teaching, research and outreach for more than 150 years. MSU is known internationally as a major public university with global reach and extraordinary impact. Its 17 degree-granting colleges attract scholars worldwide who are interested in combining education with practical problem solving.

For MSU news on the Web, go to news.msu.edu.

Michigan State University

Related Robots Articles from Brightsurf:

On the way to lifelike robots
In order for robots to be able to achieve more than simple automated machines in the future, they must not only have their own ''brain''.

Children think robots can help the elderly -- but not their own grandparents
A study that asked children to assess three different robots showed that they responded most positively to simple robots shaped like flower pots, and were most sceptical of Pepper the robot, which looks more human.

Nanomaterial gives robots chameleon skin
A new film made of gold nanoparticles changes color in response to any type of movement.

How many jobs do robots really replace?
MIT economist Daron Acemoglu's new research puts a number on the job costs of automation.

Robots popular with older adults
A new study by psychologists from the University of Jena (Germany) does not confirm that robot skepticism among elder people is often suspected in science.

Showing robots how to do your chores
By observing humans, robots learn to perform complex tasks, such as setting a table.

Designing better nursing care with robots
Robots are becoming an increasingly important part of human care, according to researchers based in Japan.

Darn you, R2! When can we blame robots?
A recent study finds that people are likely to blame robots for workplace accidents, but only if they believe the robots are autonomous.

Robots need a new philosophy to get a grip
Robots need to know the reason why they are doing a job if they are to effectively and safely work alongside people in the near future.

How can robots land like birds?
Birds can perch on a wide variety of surfaces, thick or thin, rough or slick.

Read More: Robots News and Robots Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.