Deep-eutectic solvents enable tunable control of the micro-mechanical response through electrical actuation

Abbá, Erik; Axinte, Dragos; Speidel, Alistair; Liao, Zhirong

Abstract

Active interactions at liquid-to-solid interfaces can significantly impact the mechanical response of solid substrates. Traditionally, these have been regulated through surface-active media, such as ionic liquids, used in a static (time-invariant) manner that relies on chemical tuning to induce specific mechanochemical responses. This study introduces a novel and sustainable class of Deep Eutectic Solvents (DESs) to demonstrate a dynamic (time-variant) mechanochemical effect, achieved through molecular electro-actuation at the fluid-to-solid interface. The dynamic micro-mechanochemical effect was demonstrated using a DES mixture consisting of citric acid and choline chloride in a 1:1 M ratio, applied to a nickel single-crystal micro-cantilever substrate. The findings show how the DES coating alone induced compressive surface stress, resulting in a 34 % increase in principal stress. More notably, when the substrate surface was polarized with a ±5 V potential, electro-actuation amplified this mechanochemical effect by up to 51 %, confirming a clear dynamic response. Further validation was presented at the macroscale in a polycrystalline material setting, where a similar response was observed. These findings give insight into the possible development of smart surfaces coated with DESs, where a single chemical system can dynamically alter materials’ mechanical response through simple electro-actuation, offering versatile applications across micro and macro scales.

Citation

Abbá, E., Axinte, D., Speidel, A., & Liao, Z. (2025). Deep-eutectic solvents enable tunable control of the micro-mechanical response through electrical actuation. Materials Today, 86, 183-201. https://doi.org/10.1016/j.mattod.2025.03.022

• Journal Article Type: Article
• Acceptance Date: Mar 29, 2025
• Online Publication Date: Apr 21, 2025
• Publication Date: 2025-07
• Deposit Date: Apr 24, 2025
• Publicly Available Date: Apr 24, 2025
• Journal: Materials Today
• Print ISSN: 1369-7021
• Electronic ISSN: 1369-7021
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 86
• Pages: 183-201
• DOI: https://doi.org/10.1016/j.mattod.2025.03.022
• Public URL: https://nottingham-repository.worktribe.com/output/48095211
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1369702125001440?via%3Dihub