A flexible and stretchable photonic crystal film with sensitive structural color-changing properties for spoiled milk detection

Do Thi Vien Thao; Wei-Tzu Weng; Nguyen Van Hieu; Cheng-Chung Chang; Gou-Jen Wang

doi:10.1016/j.fochx.2022.100526

A flexible and stretchable photonic crystal film with sensitive structural color-changing properties for spoiled milk detection

Food Chem X. 2022 Nov 24:16:100526. doi: 10.1016/j.fochx.2022.100526. eCollection 2022 Dec 30.

Authors

Do Thi Vien Thao¹, Wei-Tzu Weng², Nguyen Van Hieu³, Cheng-Chung Chang¹, Gou-Jen Wang^{1

2

4}

Affiliations

¹ Graduate Institute of Medical Engineering, National Chung-Hsing University, Taichung 40227, Taiwan.
² Department of Mechanical Engineering, National Chung-Hsing University, Taichung 40227, Taiwan.
³ Department of Physics and Electronics Engineering, University of Science, Ho Chi Minh City, Viet Nam.
⁴ Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.

Abstract

This study proposes a flexible and stretchable 3D polymer film with photonic crystals for the visible detection of spoiled milk. Thermoplastic polyurethane (TPU) was used as the substrate for the photonic crystal structure. The back barrier layer with a regular array of nanohemispheres of anodic aluminum oxide film was used as a template for electroforming a nickel mold. The nanohemisphere array was then nanoimprinted onto the TPU substrate to form a strain-controllable photonic crystal (SCPC) structure on it. Food spoilage can be easily detected by the structural color change caused by the gas it produces. Experimental results confirmed that the structural color change of the fabricated SCPC TPU film occurred when the elongation (ΔL) of the film reached 0.2 mm (1.2 %). Furthermore, spoiled milk detection experiments showed that the proposed SCPC TPU film is a highly intelligent and cost-effective biosensor for detecting spoiled food in a container.

Keywords: Flexible and stretchable photonic crystals; Nanimprinting; Spoiled milk detection; Strain-controllable structural color change.