Spray‐Dried Photonic Balls with a Disordered/Ordered Hybrid Structure for Shear‐Stress Indication

Language
en
Document Type
Article
Issue Date
2023-04-20
First published
2022-12-01
Issue Year
2022
Authors
Wenderoth, Sarah
Bleyer, Gudrun
Endres, Jakob
Prieschl, Johannes
Vogel, Nicolas
Wintzheimer, Susanne
Mandel, Karl
Editor
Abstract

Abstract Optical microscale shear‐stress indicator particles are of interest for the in situ recording of localized forces, e.g., during 3D printing or smart skins in robotic applications. Recently developed particle systems are based on optical responses enabled by integrated organic dyes. They thus suffer from potential chemical instability and cross‐sensitivities toward humidity or temperature. These drawbacks can be circumvented using photonic balls as shear‐stress indicator particles, which employ structural color as the element to record forces. Here, such photonic balls are prepared from silica and iron oxide nanoparticles via the scalable and fast spray‐drying technique. Process parameters to create photonic balls with a disordered core and an ordered particle structure toward the exterior of the supraparticles are reported. This hybrid disordered–ordered structure is responsible for a color loss of the indicator particles during shear‐stress application because of irreversible structural destruction. By adjusting the primary silica particle sizes, nearly all colors of the visible spectrum can be achieved and the sensitivity of the response to shear stress can be adjusted.

Journal Title
Small
Volume
18
Issue
48
Citation
Small 18.48 (2022): 2203068. <https://onlinelibrary.wiley.com/doi/10.1002/smll.202203068>