Characterization and detection of acceleration-induced cavitation in soft materials using a drop-tower-based...

Area of Science:

• Biomaterials Science
• Mechanical Engineering
• Medical Physics

Background:

• Assessing the mechanical properties of soft biological materials under high strain rates is crucial for understanding medical phenomena like brain injury and medical device interactions.
• Traditional testing methods are often unsuitable for delicate soft samples due to direct contact requirements.

Purpose of the Study:

• To develop and validate a novel drop-tower-based testing system for evaluating the high-rate material response of soft biological samples.
• To experimentally determine the critical acceleration for cavitation nucleation in pure water and 7.5% gelatin.
• To demonstrate a non-optical method for detecting cavitation in soft materials.

Main Methods:

• A drop-tower system was designed with a specialized sample holder, springs, and dampers for controlled high-rate loading.
• Theoretical analysis of transient dynamics guided the system's development.
• Experimental quantification of critical acceleration for cavitation onset in pure water and 7.5% gelatin.
• Cavitation detection was achieved by correlating collapse events with the structural resonance of the sample container.

Main Results:

• The drop-tower system enables controlled, high-rate loading of soft samples without direct contact.
• 7.5% gelatin exhibits a critical acceleration for cavitation nucleation approximately double that of pure water.
• A non-optical method for detecting cavitation in soft materials was successfully demonstrated.

Conclusions:

• The developed drop-tower method is effective for studying the high-rate mechanical response and cavitation behavior of soft biological materials.
• Biological soft materials like gelatin show distinct cavitation resistance compared to pure water.
• Non-optical cavitation detection offers a viable alternative for soft material analysis.