October 12, 2015Robotic finger mimics human digits as it is heated and cooled

The team says the robotic finger could help to overcome some of the challenges encountered by researchers working in the ocean depths (Credit: Florida Atlantic University)

Image Gallery (3 images)

Scientists at Florida Atlantic University have employed a novel thermal training technique to give robotic fingers a natural look and feel. With the ability to curve and straighten as it is heated and cooled, the researchers are hopeful their lifelike new creation will be put to use in underwater robotics and eventually, advanced prosthetic devices.

The researchers began with a 3D CAD model of a human finger. From this, they created a model of the digit and then 3D printed inner and outer molds, between which they placed a flexor and extensor actuator made from shape memory allow (SMA), along with a position sensor.

The flexor actuator was trained to take the shape of a bent human finger when heated, while the extensor was trained to straighten out when heated. So by alternately heating and cooling the two actuators, the finger in could be made to bend and straighten. This was done through a process called Joule heating, which sees electrical currents pass through a heat-generating conductor.

One problem the researchers encountered was the time it takes for each actuator to cool again and resume its natural shape after being heated. Because of this, they are looking to undersea robotics as the finger's first port of call. In an underwater environment, thermal insulators fitted to the tip of the finger can allow water to flow throughout the cavity and more efficiently cool the actuators, which the researchers say greatly improves the operational speed of the device.

Eventually it is hoped that the approach can be used fin the development of better prostheses.

"We have been able to thermomechanically train our robotic finger to mimic the motions of a human finger like flexion and extension," says Erik Engeberg, assistant professor at FAU. "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."

The research was published in the journal Bioinspiration & Biomimetics.

機械手指能夠模仿人類手指受熱和手冷時的情形

Robotic手指模仿人類的??數字，因為它被加熱和cooled

該小組說，機器人的手指可以幫助克服一些研究人員在海洋深處工作所遇到的挑戰（圖片來源：佛羅裏達大西洋大學）

圖片廊（3圖像）

科學家在佛羅裏達大西洋大學已經採用了一種新的熱訓練技術給機器人的手指一個自然的外觀和感覺。隨著和拉直，因為它被加熱和冷卻能力麯線，研究人員希望他們的栩栩如生的新的創造將投放水下機器人，最終，先進的假肢裝置使用。

研究人員開始了與人類的三維CAD模型手指。從這一點，他們創建的數字的一個模型，然後三維印刷內和外模，在它們之間它們置於一個屈肌和伸肌激勵器由形狀記憶製成允許（SMA），還有一個位置傳感器。

屈緻動器被訓練採取彎麯的人的手指的形狀，當加熱，而伸肌被訓練理順加熱時。因此，通過交替地加熱和冷卻所述兩個緻動器，所述手指可以作出彎麯和伸直。這是通過一個稱為焦耳加熱過程，看到的電流通過發熱導體完成。研究者遇到

一個問題是它需要對每個緻動器，以再次冷卻，加熱後恢複其自然形狀的時間。正因為如此，他們正在尋找國際海底機器人呼叫的手指的第一個端口。在水下環境中，熱絕緣體裝配到指尖可以允許水流在整個腔和更有效地冷卻所述緻動器，其中，研究人員錶示極大地提高了裝置的運行速度。

最終，它希望該方法可用於散熱片更好的假體的發展。

“我們已經能夠熱機械訓練我們的機器人手指模仿人類手指的動作就像屈伸，”埃裏克Engeberg說，副教授FAU。 “由於其重量輕，靈巧和力量，我們的機器人設計提供了極大的優勢，比傳統的機製，最終可能適於用作假肢裝置，如一個假手。”

這項研究發錶在雜誌Bioinspiration和放大器; 。仿生學