High-velocity micro-particle impact on gelatin and synthetic hydrogel

Abstract

The high-velocity impact response of gelatin and synthetic hydrogel samples is investigated using a laser-based microballistic platform for launching and imaging supersonic micro-particles. The micro-particles are monitored during impact and penetration into the gels using a high-speed multi-frame camera that can record up to 16 images with nanosecond time resolution. The trajectories are compared with a Poncelet model for particle penetration, demonstrating good agreement between experiments and the model for impact in gelatin. The model is further validated on a synthetic hydrogel and the applicability of the results is discussed. We find the strength resistance parameter in the Poncelet model to be two orders of magnitude higher than in macroscopic experiments at comparable impact velocities. The results open prospects for testing high-rate behavior of soft materials on the microscale and for guiding the design of drug delivery methods using accelerated microparticles.

Gelatine cavity dynamics of high-speed sphere impact

“…While the dynamics of surface-seal cavities has not been explored in past literature with excessive detail, the fluidic behaviour that is reported is quite similar to our findings. Veysset et al (2018) showed that the impact of a copper microparticle at 435 m s −1 can cause surface dome-over at the surface of a protein hydrogel. Their maximum radius R L /R is found to be R L /R ≈ 5, which is comparable to that obtained from our surface-seal data.…”

“…Veysset et al. (2018) showed that the impact of a copper microparticle at can cause surface dome-over at the surface of a protein hydrogel. Their maximum radius is found to be , which is comparable to that obtained from our surface-seal data.…”

“…2014; Veysset et al. 2018). Here we find that while the cavities formed by spheres penetrating gelatine and water have some differences, they share many similarities as well.…”

Laser-driven high-velocity microparticle launcher in atmosphere and under vacuum

“…Microparticles are then deposited on the substrates and spread on the metallic layer using lens cleaning papers and a drop of ethanol. Optionally, an elastomeric layer (30-μm polyurea, not shown in schematics) may be added onto the metallic film before deposition of particles as described, for instance, in Refs [17,25]. In the present case, particles reach higher velocities but are in direct contact with the ablation area.…”

Molecular dependencies of dynamic stiffening and strengthening through high strain rate microparticle impact of polyurethane and polyurea elastomers

“…The laser-induced particle impact test (LIPIT) is an in-house designed tabletop method for micro-impact experiments. 23 The LIPIT is capable of inducing impacts with strain rates on the order of 10 6 -10 8 s -1 and has been used for testing high strain rate impact responses in gels 24 , segmented elastomers [19][20][21]25 , and other various materials [26][27][28] . Using this platform, Hsieh et al found that intersegmental mixing between the soft and hard phases strongly affected the high strain rate impact response of poly(urethane urea) and polyurea elastomers 21 .…”