High-speed, 3D volumetric displacement and strain mapping in soft materials using Light Field Microscopy

Published

September 2, 2022

Author(s)

Selda Buyukozturk, Alexander Landauer, Jing Zhang, Luke Summey, Angel Chukwu, Christian Franck

Abstract

Background: High strain-rate deformations of soft materials have several applications which presents an experimental need to measure at-rate 3D volumetric spatial information. While 2D- and 3D-digital image correlation, digital volume correlation, and particle tracking techniques have been able to reconstruct full-field displacements with great resolution, experimentally obtaining volumetric information and applying these techniques at high rates remains a significant challenge, especially at small, micrometer length scales. Methods: To conduct 3D volumetric imaging at high (100 Hz to 10 kHz) or ultra-high rates (10+ kHz) we designed a full-field volumetric light-field microscopy system paired with post-processing and volumetric particle tracking routines to quantify 3D volumetric deformations. Light field microscopy uses the principles of low-angle tomographic volume reconstruction with a microlens array to generate parallax within a single 2D image, which is used for volume reconstruction of a transparent material seeded with fluorescent particles. The algorithm then segments and localizes the particles, and tracks the cumulative motion of the particles throughout a reconstructed image volume. Results: To validate the technique, both synthetic images and gels with embedded particles underwent deformations at high strain-rates.We simulate the light-field representation of particles undergoing motion with ray tracing and investigate the sensitivity and noise floor of the measurement technique. In experiments, a custom-built simple shear device deformed the gel at assorted applied strain rates, while light-field images were collected at between 500 frames per second and 2000 frames per second. Conclusion: By combining light field microscopy with our recently developed topology-based 3D particle tracking algorithms we demonstrate accurate resolution of volumetric displacement fields in soft, transparent materials undergoing high rate deformations.

Citation

Experimental Mechanics

Pub Type

Journals

Download Paper

https://doi.org/10.1007/s11340-022-00885-z

Local Download

Keywords

Light Field Microscopy, High speed tomographic imaging, Particle tracking, 3D deformations

Citation

Buyukozturk, S. , Landauer, A. , Zhang, J. , Summey, L. , Chukwu, A. and Franck, C. (2022), High-speed, 3D volumetric displacement and strain mapping in soft materials using Light Field Microscopy, Experimental Mechanics, [online], https://doi.org/10.1007/s11340-022-00885-z, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932900 (Accessed May 9, 2024)