Bipedal nanowalker by pure physical mechanisms

TL;DR

This paper introduces a light-powered DNA nanowalker that moves directionally through pure physical mechanisms, avoiding chemical waste and inspired by cellular walkers, with potential for broader nanomachine applications.

Contribution

It presents a novel physical mechanism-based design for a DNA nanowalker that achieves directed motion without chemical waste, inspired by biological systems.

Findings

Achieves directional movement via intra-site asymmetry and ratchet effect.

Operates without chemical waste, using physical mechanisms.

Maintains thermodynamic equilibrium before and after operation.

Abstract

Artificial nanowalkers are inspired by biomolecular counterparts from living cells, but remain far from comparable to the latter in design principles. The walkers reported to date mostly rely on chemical mechanisms to gain a direction; they all produce chemical wastes. Here we report a light-powered DNA bipedal walker based on a design principle derived from cellular walkers. The walker has two identical feet and the track has equal binding sites; yet the walker gains a direction by pure physical mechanisms that autonomously amplify an intra-site asymmetry into a ratchet effect. The nanowalker is free of any chemical waste. It has a distinct thermodynamic feature that it possesses the same equilibrium before and after operation, but generates a truly non-equilibrium distribution during operation. The demonstrated design principle exploits mechanical effects and is adaptable for use in other nanomachines.