Acoustic-soft material interactions: Improved mechanistic understanding driving innovative biomedical applications
Aarushi Bhargava, PhD
Humboldt Postdoctoral Fellow
Physical Intelligence Department
Max Planck Institute for Intelligent Systems, Stuttgart, Germany
The primary application of ultrasound in medical sciences has traditionally been limited to imaging. Meanwhile, tremendous advancements in adjacent applications of acoustic-structure interaction such as wireless energy transfer, remote stimulation, and soft robotics have been made. The past decade features rapid growth of research bringing together these areas towards developing innovative biomedical technologies for non-invasive diagnostics and therapeutics. In this talk, we will discuss fundamental aspects of the interaction of ultrasound with soft materials and resulting contemporary applications using different acoustic intensities. The interactions are investigated for three material-types leading to different biomedical applications: shape memory polymers for drug delivery, piezoelectrics for wireless powering of implants, and biological materials such as blood clots for therapy. A concept of achieving spatiotemporal control on drug release using ultrasound-responsive shape memory polymer-based capsules will be presented. We will uncover the underlying mechanism and the use of nonlinear sound waves to enhance the polymer response controlling drug release. Next, we will discuss how nonlinearity in ultrasound waves can enhance power output from piezoelectric receivers, thus minimizing low efficiency issues in existing wireless energy transfer systems. Finally, we will explore the interaction of ultrasound with biological tissues in the context of histotripsy, a potential adjuvant for treating blood clots. Histotripsy is a mechanism to disintegrate tissues using bubbles generated via ultrasound shock waves. We will demonstrate the changes in histotripsy bubble dynamics in the presence of drug-carrying liposomes, and their potential to enhance treatment efficiency.