# Parametric Optimization of Microcontact Stamping for Rapid Thermo-Color Change in Pigment-Coated Thin Film

## TL;DR

This paper optimizes microcontact stamping to create thin films that change color rapidly with temperature, enabling potential use in smart devices.

## Contribution

The study provides a systematic parametric optimization for fabricating thermochromic micro-patterns using microcontact stamping.

## Key findings

- Optimal conditions include UV-curable resin, 600 µm SU-8 mold, 5:1 PDMS ratio, and 125 × 125 µm² pattern size.
- Stamped films showed uniform patterns, rapid color response, and stability over 20 thermal cycles.
- The method is suitable for scalable fabrication of thermochromic micro-patterns on flexible substrates.

## Abstract

Microcontact stamping is a promising microfabrication technique for producing functional patterned thin films on flexible substrates; however, systematic optimization of its process parameters for thermochromic applications remains limited. In this study, we present a comprehensive parametric optimization of the microcontact stamping process to fabricate thermochromic pigment-coated thin films with rapid and reversible color responses. The effects of liquid resin type, SU-8 mold thickness, polydimethylsiloxane (PDMS) mixing ratio, and pattern size on pattern fidelity and thermochromic performance were systematically investigated. The optimal conditions were identified as a UV-curable resin, a 600 µm-thick SU-8 mold, a PDMS base-to-curing-agent ratio of 5:1, and a pattern size of 125 × 125 µm2. Under these conditions, the stamped thermochromic films exhibited uniform micro-patterns, rapid response and recovery behavior, and stable reversible color changes over 20 consecutive thermal cycles. This work provides practical guidelines for parameter-controlled microcontact stamping of functional thin films and demonstrates its potential for scalable fabrication of thermochromic micro-patterns. The proposed approach is expected to contribute to the development of flexible and wearable electronic devices, smart displays, and thermally responsive sensing platforms.