Multistable energy landscapes for adaptive microscopic machines

TL;DR

This paper demonstrates how designing multistable energy landscapes in microscopic machines allows a single external field to induce multiple functions and adaptive responses, advancing autonomous microscale device capabilities.

Contribution

It introduces the concept of multistable energy landscapes to enable adaptive, multifunctional microscopic machines driven by the same external field, with three illustrative examples.

Findings

Bistable energy landscape enables two stable configurations under the same magnetic field.

Adding a second degree of freedom allows different dynamic responses to the same external field.

Machines with continuous symmetry can autonomously convert magnetic actuation into locomotion and adapt to external forces.

Abstract

The past few years have seen great strides in our ability to build synthetic microscopic machines. However, the function of such machines is often controlled directly by externally applied fields that deterministically specify the instantaneous machine dynamics. A crucial step towards machines that can respond adaptively to changes in their environment is the ability to program multiple functions that actuate under the same external driving field, so that their internal state dictates which function is executed. Here, we demonstrate that energy landscapes with designed multistability enable the same externally applied field to drive multiple configurations and dynamic responses in microscopic machines, enabling increasing levels of autonomy. We show three examples. First, we write a bistable energy landscape into a microscopic device, enabling the device to exhibit two stable mechanical configurations under the same external magnetic field. Next, adding a second degree of freedom enables differing dynamic responses to the same external magnetic field, which we direct into net displacement of the environment. Finally, we demonstrate how a microscopic machine with a continuous symmetry autonomously channels a single degree-of-freedom magnetic actuation into locomotion and adaptively responds to forces induced by other machines.