22 MOMENTUM • VIRGINIA TECH MECHANICAL ENGINEERING
MELTING , MORPHING ,
New soft robot morphs from a ground to air vehicle using liquid metal
Imagine a small autonomous vehicle that could drive over land , stop , and flatten itself into a quadcopter . The rotors start spinning , and the vehicle flies away . Looking at it more closely , what do you think you would see ? What mechanisms have caused it to morph from a land vehicle into a flying quadcopter ? You might imagine gears and belts , perhaps a series of tiny servo motors that pulled all its pieces into place .
If this mechanism was designed by a team at Virginia Tech led by Michael Bartlett , assistant professor in mechanical engineering , you would see a new approach for shape changing at the material level . These researchers use rubber , metal , and temperature to morph materials and fix them into place with no motors or pulleys . The team ’ s work has been published in Science Robotics . Co-authors of the paper include graduate students
Dohgyu Hwang and Edward J . Barron III and postdoctoral researcher A . B . M . Tahidul Haque .
Getting into shape
Nature is rich with organisms that change shape to perform different functions . The octopus dramatically reshapes to move , eat , and interact with its environment ; humans flex muscles to support loads and hold shape ; and plants move to capture sunlight throughout the day . How do you create a material that achieves these functions to enable new types of multifunctional , morphing robots ?
“ When we started the project , we wanted a material that could do three things : change shape , hold that shape , and then return to the original configuration , and to do this over many cycles ,” said Bartlett . “ One of the challenges was to create a material that was soft enough to dramatically change shape ,