Cambridge, Massachusetts – Scientists at the Harvard John A. Paulson School of Engineering and Applied Sciences have made a groundbreaking discovery in metamaterial technology. Researchers have developed a versatile programmable metafluid, a type of fluid that can adjust its properties – including viscosity and optical transparency – in response to pressure. This innovative metafluid has the potential for wide-ranging applications in fields such as robotics, optical devices, and energy dissipation.
The metafluid developed by the Harvard research team consists of small elastomer spheres suspended in a liquid that buckle under pressure, fundamentally changing the characteristics of the fluid. This unique fluid can be used in various applications, from hydraulic actuators to robotics programming, to advanced shock absorbers capable of dissipating energy based on impact intensity, to optical devices that can switch from opaque to transparent with ease.
Unlike traditional solid metamaterials, metafluids have the remarkable ability to flow and adapt to the shape of their container. Through a scalable fabrication technique, researchers created hundreds of thousands of deformable spherical capsules filled with air and suspended them in silicon oil. When pressure is applied, the capsules collapse, altering the properties of the fluid. When pressure is released, the capsules return to their original spherical shape.
The programmable nature of the metafluid allows for customization of its viscosity, compressibility, and optical properties by adjusting the number, thickness, and size of the capsules within the liquid. This flexibility was demonstrated by loading the metafluid into a hydraulic robotic gripper, showcasing the fluid’s ability to adjust its grip strength to pick up objects of varying weights without the need for additional sensing or external control.
In addition to its mechanical properties, the metafluid also exhibits dynamic changes in its optical properties when subjected to pressure. When the capsules are round, they scatter light, rendering the fluid opaque. However, when the capsules collapse, they act as microlenses, focusing light and rendering the fluid transparent. These optical properties have potential applications in technologies like color-changing e-inks based on pressure.
The research team’s next steps involve exploring the acoustic and thermodynamic properties of the metafluid. With its scalability and ease of production, metafluids offer vast potential for various commercial applications. The Harvard Office of Technology Development has already taken steps to protect the intellectual property associated with this research and is actively exploring opportunities for commercialization.
This groundbreaking research, supported in part by the NSF through the Harvard University Materials Research Science and Engineering Center grant, represents a significant leap forward in metamaterial technology. The development of programmable metafluids opens up a world of possibilities for innovation across multiple fields, showcasing the endless potential of this new class of fluid.