Single-Component TiO2 Tubular Microengines with Motion Controlled by Light-Induced Bubbles

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Micro- and nanomotors are crucial for targeted delivery and environmental remediation.
• Bubble propulsion is an efficient mechanism for micro-engine locomotion.
• Developing single-component, light-responsive microengines remains a challenge.

Purpose of the Study:

• To demonstrate the first light-controlled, bubble-propelled single-component metal oxide tubular microengines.
• To investigate the propulsion mechanism and motion control of TiO2 tubular microengines.
• To explore potential photocatalytic applications of these microengines.

Main Methods:

• Fabrication of single-component TiO2 tubular microengines with controlled dimensions.
• Utilizing hydrogen peroxide (H2O2) aqueous solution as a fuel source.
• Employing UV irradiation to trigger and control bubble nucleation and microengine propulsion.

Main Results:

• TiO2 tubular microengines exhibited preferential O2 bubble nucleation on the inner surface, driving propulsion.
• Microengine speed and motion state were reversibly controlled by adjusting UV irradiation.
• Fast response times (less than 0.2 s) and wireless control were achieved.
• The microengines demonstrated potential for 'on-the-fly' photocatalytic degradation and inactivation.

Conclusions:

• Light-controlled bubble propulsion in single-component TiO2 tubular microengines has been successfully demonstrated.
• The facile fabrication, low cost, and controllable motion enable promising applications in photocatalysis.
• These microengines offer a versatile platform for environmental remediation and antimicrobial strategies.