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Using Small Molecule Absorbers to Create a Photothermal Wax Motor
Brandon F Lui1, Christopher J Bardeen1,2
1Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA.
Small (Weinheim an Der Bergstrasse, Germany)
|December 2, 2021
Summary
Small molecules enable light-powered wax motors by inducing phase changes in organic materials. This non-contact method offers a new way to activate actuators like wax motors using light energy.
Area of Science:
- Materials Science
- Actuator Technology
Background:
- Organic phase change materials are crucial for actuators like wax motors, typically requiring electrical resistive heating for solid-liquid transitions.
- Non-contact actuation methods are desirable for powering such devices.
Purpose of the Study:
- To demonstrate a non-contact method for actuating wax motors using light.
- To enable photoinduced solid-liquid phase transitions in eicosane using small molecule absorbers.
Main Methods:
- Incorporation of small molecule absorbers (TEMPO, AZOB, GAZ) into eicosane, a phase change material.
- Characterization of the GAZ/eicosane mixture for its absorption properties up to 750 nm.
- Integration of the GAZ/eicosane composite into a commercial wax motor and actuation using 532 nm laser light.
Main Results:
- Demonstrated photoinduced solid-liquid melting transition in eicosane using small molecule absorbers.
- Successful actuation of a commercial wax motor lifting up to 400 g using laser light.
- No degradation or loss of performance observed after ten irradiation cycles.
Conclusions:
- Small aromatic molecules with low-energy absorption can be integrated into phase change materials to create light-powered wax motors.
- This approach offers a general strategy for developing non-contact, light-activated actuators.
