Hygrobot: A self-locomotive ratcheted actuator powered by environmental humidity

Microrobots that are light and agile yet require no artificial power input can be widely used in medical, military, and industrial applications. As an actuation system to drive such robots, here we report a biologically inspired bilayer structure that harnesses the environmental humidity energy, wit...

Full description

Saved in:
Bibliographic Details
Published in:Science robotics 2018-01, Vol.3 (14)
Main Authors: Shin, Beomjune, Ha, Jonghyun, Lee, Minhee, Park, Keunhwan, Park, Gee Ho, Choi, Tae Hyun, Cho, Kyu-Jin, Kim, Ho-Young
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Microrobots that are light and agile yet require no artificial power input can be widely used in medical, military, and industrial applications. As an actuation system to drive such robots, here we report a biologically inspired bilayer structure that harnesses the environmental humidity energy, with ratchets to rectify the motion. We named this actuator-ratchet system the hygrobot. The actuator uses a hygroscopically responsive film consisting of aligned nanofibers produced by directional electrospinning, which quickly swells and shrinks in lengthwise direction in response to the change of humidity. The ratchets based on asymmetric friction coefficients rectify oscillatory bending motion in a directional locomotion. We mathematically analyzed the mechanical response of the hygrobot, which allowed not only prediction of its performance but also the optimal design to maximize the locomotion speed given geometric and environmental constraints. The hygrobot sterilized a trail across an agar plate without any artificial energy supply.
ISSN:2470-9476
2470-9476
DOI:10.1126/scirobotics.aar2629