May 3, 2023

News Want a FREE PDF version of this news story? Complete the form below and we will email you a PDF version of "“Microbots” Demonstrate How Biological Machines Move" First Name* Send my copy ✖ Technology Networks Ltd. needs the contact information you provide to us to contact you about our products and services. You may unsubscribe from these communications at any time. For information on how to unsubscribe, as well as our privacy practices and commitment to protecting your privacy, check out our Privacy Policy Listen with Thank you. Listen to this article using the player above. ✖ Want to listen to this article for FREE? Complete the form below to unlock access to ALL audio articles. ✖ Technology Networks Ltd. needs the contact information you provide to us to contact you about our products and services. You may unsubscribe from these communications at any time. For information on how to unsubscribe, as well as our privacy practices and commitment to protecting your privacy, check out our Privacy Policy Read time: ‘Hexbug Nano v2’ microbots use vibrations to propel themselves forward. By connecting several of these toys with an elastic silicon rubber chain, the resulting structure is ‘elastoactive’. This means that it will return to its original shape after being deformed, while the self-propelling, active constituents that it is comprised of constantly try to push the structure in a certain direction. Depending on the size of the chain links and whether the chains were fixed at one or both ends, the elastoactive chains showed a range of movement types, including self-oscillatory, self-synchronising and self-snapping. “By experimenting with these elastoactive chains, we discovered that there is an interplay between activity and elasticity: when activity dominates, the chains self-oscillate and synchronize,” says Corentin Coulais, head of the  Machine Materials Laboratory  at the University of Amsterdam. Want more breaking news? Self-oscillation, self-synchronisation and self-snapping When a structure self-oscillates, this means that it bends back and forth by itself. In the chains, the microbots might start by bending the chain to the left. However, because the chain is pinned at one end, the elastic links resist this movement, reorienting the bots in such a way that they start pushing and bending the chain to the right. This movement will again be resisted by the elastic chain, until the bots start moving to the left again. Synchronisation happens when two elastoactive chains are connected at one end by a stiff enough rod. By wriggling around, the two connected chains automatically start oscillating with the same frequency, like sea grasses moved by the same waves. Finally, taking a single elastoactive chain and pinning both of its ends, it shows ‘self-snapping’ behaviour. When you bend a playing card with your fingers, you can make it ‘snap’ to bending the other way by pushing hard enough from the side. The elastoactive chains do this by themselves, repeatedly snapping from bending to the left to bending to the right. Instructive play “We started this research by just playing around with the microbot toys. But more generally, the idea was to explore materials out of equilibrium. In soft matter, active fluids have been studied extensively in the last 25 years, but their solid counterparts were investigated much less,” says Coulais. Next on the menu is exploring elastoactive behaviour at smaller scales, for instance in so-called colloidal systems, consisting of small particles suspended in a fluid. Even though these are still model systems, they are closer to the biological system due to similar length scales and the presence of the fluid. At any scale, it would also be interesting to use smart design to embed multiple self-oscillations within a single structure to obtain more complex movement patterns. With a better understanding of self-oscillations, the hope is that it becomes possible to create new types of autonomous robots. Reference: Zheng E, Brandenbourger M, Robinet L, Schall P, Lerner E, Coulais C. Self-Oscillation and synchronization transitions in elastoactive structures. Phys Rev Lett. 2023;130(17):178202. doi:  10.1103/PhysRevLett.130.178202 This article has been republished from the following materials . Note: material may have been edited for length and content. For further information, please contact the cited source. Advertisement