4D printing of electro-activated thermochromic composites for dynamic 3D displays
No Thumbnail Available
Access rights
openAccess
CC BY
CC BY
publishedVersion
URL
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
Date
2025-03
Major/Subject
Mcode
Degree programme
Language
en
Pages
11
Series
Materials & Design, Volume 251
Abstract
This paper introduces a novel 4D printing approach for dynamic displays, using thermochromic-PLA composites embedded with FeCrAl wires activated by Joule heating. Previous studies struggled with high energy consumption, heat bleed, and slow activation. By embedding continuous resistance wires directly within the thermochromic-plastic matrix, localized, efficient heating is achieved, improving response speed and energy efficiency. The study optimizes color change by focusing on specimen thickness, current intensity, and pulse duration. A customized G-code workflow allowed for precise wire integration into 3D-printed specimens fabricated using a composite dual-nozzle co-extrusion printer, enabling controlled color changes upon activation. Experiments identified 1.5 mm as the ideal specimen thickness, balancing rapid response time (∼78.5 s for 80 % color change) with effective wire concealment. A water medium significantly accelerated recovery time compared to air, emphasizing the benefits of faster heat dissipation. The color change was found to be linearly proportional to pulse-on time and the square of the current. Shorter pulses at higher currents resulted in more efficient and predictable color transformations than constant current inputs. A functional 7-segment display was fabricated, demonstrating the practical application of this technology for smart displays, sensors, and other 4D-printing applications.Description
Keywords
Color change dynamics, Electroactivated displays, Material extrusion (MEX), Multi-material printing, Thermochromic PLA filament, mic PLA filament
Other note
Citation
Kumar, S S, Niyagama, W W, Akmal, J S & Salmi, M 2025, ' 4D printing of electro-activated thermochromic composites for dynamic 3D displays ', Materials & Design, vol. 251, 113674 . https://doi.org/10.1016/j.matdes.2025.113674