A researcher at Florida Atlantic University (FAU) recently designed a robotic finger that he suggests looks and feels like the real thing.

In a study recently published in Bioinspiration & Biomimetics, Erik Engeberg, PhD, notes that he developed and tested the robotic finger using shape memory alloy (SMA), a 3D CAD model of a human finger, a 3D printer, and a unique thermal training technique, according to a media release from Florida Atlantic University.

“We have been able to thermomechanically train our robotic finger to mimic the motions of a human finger like flexion and extension,” says Engeberg, assistant professor in the Department of Ocean and Mechanical Engineering within the College of Engineering and Computer Science at FAU, in the release.

“Because of its light weight, dexterity, and strength, our robotic design offers tremendous advantages over traditional mechanisms, and could ultimately be adapted for use as a prosthetic device, such as on a prosthetic hand,” he adds.

In the study, Engeberg and his team used a resistive heating process called “Joule” heating that involves the passage of electric currents through a conductor that releases heat. Using a 3D CAD model of a human finger, which they downloaded from a website, they were able to create a solid model of the finger. With a 3D printer, they created the inner and outer molds that housed a flexor and extensor actuator and a position sensor. The extensor actuator takes a straight shape when it’s heated, whereas the flexor actuator takes a curved shape when heated, the release explains.

They used SMA plates and a multi-stage casting process to assemble the finger. An electrical chassis was designed to allow electric currents to flow through each SMA actuator. Its U-shaped design directed the electric current to flow the SMAs to an electric power source at the base of the finger, the release continues.

This new technology used both a heating and then a cooling process to operate the robotic finger. As the actuator cooled, the material relaxed slightly. Results from the study showed a more rapid flexing and extending motion of the finger as well as its ability to recover its trained shape more accurately and more completely, confirming the biomechanical basis of its trained shape, the release notes.

“Because SMAs require a heating process and cooling process, there are challenges with this technology such as the lengthy amount of time it takes for them to cool and return to their natural shape, even with forced air convection,” Engeberg says.

“To overcome this challenge, we explored the idea of using this technology for underwater robotics, because it would naturally provide a rapidly cooling environment,” he continues.

The initial application of this finger will be used for underseas operations to help address some of the difficulties and challenges humans encounter while working in the ocean depths, according to the release.

[Source(s): Florida Atlantic University, EurekAlert]

[Photo courtesy of Bioinspiration & Biomimetics]