Viscoelastic instabilities for physically intelligent, flexible mechanical metamaterials

• Applicant: Dr. Aniket Pal
• Subject Area: Mechanics ; Applied Mechanics, Statics and Dynamics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 556707586

Integrating viscoelastic properties with mechanical instabilities allows us to exploit functionalities generated from both the material and the geometry, and this interesting intersection has very recently started to attract attention. We propose to explore a new direction, within the intersection of mechanical instability and viscoelasticity, to develop new capabilities of mechanical computation, like mechanical memory, reprogrammable functional devices, and higher order information abstraction. Viscoelastic materials are materials which exhibit both fluid- and solid-like behavior. The fluid like behavior manifests itself as a displacement- or strain-rate dependent mechanical response. On the other hand, a system is said to undergo a mechanical instability when it experiences a rapid transition due to a drastic reduction of its stiffness, leading to large deformations; a common example of which is buckling of beams. Mechanical instabilities provide a way of force and power amplification, i.e., a large and rapid deformation at very small incremental energy input. Not only rapid and large deformations, mechanical instabilities also provide access to deformation shapes not usually found through traditional modes of stretching, bending, twisting, etc. We start the project by delving into pure viscoelastic instabilities and its potential in mechanical information storage (WPA). In the next two work packages, we combine viscoelastic instabilities with magnetic actuation (WPB) and hierarchical architecture (WPC), and propose potential applications like reprogrammable logical devices and N-ary information abstraction in a mechanical system. All the work packages follow a similar theme; i.e., we explore the interesting mechanics arising at the intersection of viscoelasticity and mechanical instabilities, gain a complete understanding of the mechanics, and use it to enable new capabilities in mechanical computing. These capabilities will pave the way for developing autonomous soft robots and embedding physical intelligence in soft machines. Soft robots - robots made out of physically soft materials - actuate through the deformation of their physical body. The combination of the large deformation capabilities of soft materials and the responsiveness of active materials in soft robotics have led to the paradigm of physical intelligence where the functions of the soft robot can be encoded in the physically body itself. Harnessing viscoelastic instabilities allows us to attain new functionalities in mechanical computing, which can serve to further embody the intelligence or decision making capability to the body in the robot. This is especially important in "cutting the cord" or developing untethered, autonomous soft robots, which do not have to be wired to a computer for control. Increased physical intelligence also allows us to complement traditional computational intelligence by offloading some decisions to the physical body of the system.

• DFG Programme: Emmy Noether Independent Junior Research Groups
• Major Instrumentation: Rheometer ; Universal testing machine