Magnetic-acoustic actuated spinous microrobot for enhanced degradation of organic pollutants

Shimin Yu; Chenlu Liu; Mingyang Sui; Haiqiang Wei; Haoyuan Cheng; Yujing Chen; Yanhe Zhu; Haocheng Wang; Penglei Ma; Lin Wang; Tianlong Li

doi:10.1016/j.ultsonch.2023.106714

Magnetic-acoustic actuated spinous microrobot for enhanced degradation of organic pollutants

Ultrason Sonochem. 2024 Jan:102:106714. doi: 10.1016/j.ultsonch.2023.106714. Epub 2023 Dec 14.

Authors

Shimin Yu¹, Chenlu Liu², Mingyang Sui², Haiqiang Wei³, Haoyuan Cheng¹, Yujing Chen¹, Yanhe Zhu², Haocheng Wang², Penglei Ma⁴, Lin Wang⁵, Tianlong Li⁶

Affiliations

¹ College of Engineering, Ocean University of China, Qingdao 266100, China.
² State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China.
³ The Twelfth Oil Production Plant of Changqing Oilfield Company, Qingyang 745400, China.
⁴ College of Engineering, Ocean University of China, Qingdao 266100, China. Electronic address: mplsdu@163.com.
⁵ State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China. Electronic address: linwang@hit.edu.cn.
⁶ State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China; Chongqing Research Institute of HIT, Chongqing 401151, China. Electronic address: tianlongli@hit.edu.cn.

Abstract

A growing interest in the development of efficient strategies for the removal of organic pollutants from polluted water is emerging. As such, artificial micro/nano machines performing excellent water purification tasks have recently attracted more research attention of scientists. Hereby a spinous Fe₃O₄@PPy microrobot is presented that towards an efficient organic pollutant removal by enhancing Fenton-like reaction. The microrobot is fabricated by wrapping polypyrrole (PPy) on a spiny magnetic template prepared from sunflowers pollen. Modulating the sound pressure and frequency of the ultrasonic field enables the Fe₃O₄@PPy microrobot to present multimode motion, such as violent eruption-like motion caused by local cavitation (ELM), march-like unific motion (MLM), and typhoon-like rotation toward the center gathered motion (TLM). This multimode motion achieves the sufficient locomotion of microrobots in three-dimensional space and effective contact with organic pollutants in polluted water. Furthermore, a 5.2-fold increase in the degradation rate of methylene blue has been realized using Fe₃O₄@PPy microrobots under low-concentration hydrogen peroxide conditions. Also, the magnetically controlled recovery of microrobots from water after the completion of the degradation task has been demonstrated. The magnetic-acoustic actuated spinous microrobot can be extrapolated to other catalytic microrobot, developing a new strategy for an easier implementation and recovery of microrobot in real applications of water purification.

Keywords: Degradation of methylene blue; Fe(3)O(4)@PPy microrobot; Multimode motion.