Multiscale Thermal Property Measurements for Biomedical Applications.

Area of Science:

• Biomedical Engineering
• Thermal Physics
• Materials Science

Background:

• Bioheat transfer innovations are vital for medical applications such as targeted cancer therapies, cardiovascular disease treatments, and organ preservation for transplantation.
• Precise control over biomaterial temperature history is essential for inducing or avoiding specific thermal effects, like cell death or preservation.
• Accurate thermal measurement and modeling are therefore critical for developing and optimizing these biomedical applications.

Purpose of the Study:

• To review and discuss thermal conductivity and calorimetric measurement techniques for biomaterials.
• To cover measurements across various temperature regimes: cryogenic, subzero, hypothermic, and hyperthermic.
• To highlight advancements in micro- and nanoscale thermal measurements driven by emerging biomedical needs.

Main Methods:

• Review of thermal conductivity measurement techniques, including the 3ω and laser flash methods for thin, anisotropic, and multilayered tissues.
• Discussion of nanoscale thermal conductivity measurements using pump-probe and scanning probe methods for short temporal and spatial scales, particularly around nanoparticles.
• Overview of calorimetric techniques, focusing on differential scanning calorimetry (DSC) for microscale samples and the development of nanocalorimetry for ultra-rapid analysis of minute samples.

Main Results:

• Established techniques like 3ω and laser flash are effective for bulk and thin biomaterial thermal conductivity.
• Nanoscale techniques enable precise thermal characterization at unprecedented temporal and spatial resolutions.
• Nanocalorimetry offers significant advantages for analyzing small samples at high heating rates, overcoming limitations of traditional DSC.

Conclusions:

• A comprehensive understanding of thermal properties across different scales is essential for advancing bioheat transfer applications in healthcare.
• Ongoing development of micro- and nanoscale thermal measurement techniques is crucial for future innovations in precision medicine and regenerative therapies.
• The reviewed techniques provide a foundation for precise thermal management in critical biomedical procedures.