Researchers at Harvard University’s John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a shape-shifting material that can take and take any shape possible. The invention could be a fundamental advance in science to advance fields such as robotics or space.
This breakthrough paves the way for a new type of multifunctional material It can be used in a range of applications, from robotics and biotechnology to architecture. The search was published in Proceedings of the National Academy of Sciences.
“Currently shape-shifting materials and structures can only transition between a few stable configurations, but we have shown how to create structural materials with an arbitrary range of shape-shifting capabilities.” L Mahadevan, professor of applied mathematics, organic and evolutionary biology and physics and lead author of the paper said in a statement. “These structures allow for independent control of geometry and mechanics, laying the foundation for designing functional forms using a new type of switchable unit cell.”
One of the biggest challenges in designing shape-shifting materials is balancing the seemingly contradictory needs of formability and rigidity. Adaptability allows for transformation into new shapes, but if you’re too compatible, you can’t keep shapes fixed. The stiffness helps hold the material in place, but if it’s too stiff, it won’t take on new shapes.
The team started with a neutrally stable unit cell with two rigid components, a strut and lever, and stretchable rubber springs.. If you’ve ever watched the beginning of a Pixar movie, you’ve seen still shots that are neutral. The Pixar lamp head is stable in any position because the force of gravity is always countered by springs that expand and compress in a coordinated manner, regardless of the lamp configuration. In general, systems that are neutrally stable, a mixture of hard and elastic elements balance the energy of the cells, making each of them neutrally stable, which means that they can move between an infinite number of positions or directions and be stable in any of them.
“By having a neutrally stationary unit cell, we can separate the geometry of the material from its mechanical response both individually and collectively,” Dr.Iju Gaurav Choudhury, Postdoctoral Fellow at SEAS and co-first author of the article. “The geometry of the unit cell can be altered by changing its overall size and length of the single movable strut, while its elastic response can be altered by changing the stiffness of the springs within the chassis or the length of the struts and connections.”
The researchers named the group Totorific materials Because of its ability to transform into any stable form. The researchers attached individual unit cells to naturally stable joints, building 2D and 3D structures from individual, fully-shaped cells. The researchers used mathematical models and real-world evidence to show the material’s ability to change shape.
The team showed that a single sheet of whole cells can twist and turn into a helix, shape into two different faces, and even support weight.. “We show that we can assemble these elements into structures that can take any shape with heterogeneous mechanical responses,” said S. Ganga Prasath, SEAS Postdoctoral Fellow and co-first author of the paper. “Because these materials are engineering-based, they can be scaled down for use as sensors in robotics or biotechnology or they can be scaled up for use on an architectural scale.
“Together, these whole shapes pave the way for a new class of materials whose response to deformation can be controlled at multiple levels.” Diego Mahadevan.