Bio-based visual optical pressure-responsive sensor

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Development of advanced sensors with tunable properties is crucial for next-generation technologies.
• Bio-based materials offer sustainable alternatives in materials science.
• Structural color, derived from material architecture, provides a unique sensing mechanism.

Purpose of the Study:

• To create a novel bio-based pressure-responsive sensor with adjustable structural color.
• To investigate the relationship between material structure, composition, and pressure-sensing capabilities.
• To evaluate the durability and performance of the developed sensor.

Main Methods:

• Fabrication of a cellulose nanocrystal (CNC)/poly(ethylene glycol) (PEG) aerogel via ice-templating.
• Incorporation of the aerogel with a polyacrylamide (PAAM) elastomer.
• Characterization of the aerogel's chiral nematic structure and its response to mechanical stress.
• Tuning of helical pitch and pressure sensitivity through controlled PEG and PAAM content.

Main Results:

• A white aerogel with a chiral nematic structure was successfully prepared.
• The 3D to 2D transformation of the aerogel under pressure induced structural color.
• Structural color wavelength was tunable up to 178 nm by adjusting PEG content.
• A linear correlation between pressure and reflectance peak transmittance was observed.
• Pressure sensitivity was modulated by varying PAAM solid content.
• The sensor demonstrated robust performance, retaining vivid color after 16 compression cycles.

Conclusions:

• The developed bio-based aerogel-elastomer composite functions as an effective pressure-responsive sensor with adjustable structural color.
• The material's unique structural transformation under pressure allows for visible color changes, enabling pressure detection.
• Tunable optical properties and pressure sensitivity, along with good durability, highlight its potential for applications in sensing, intelligent displays, and information transmission.