Requirements on ultrasound transducers in bioelectronics medicine applications (vor Ort)
* Presenting author
Abstract:
The research field of “bioelectronics medicine” focus on neural signaling, which affects neural and specific molecular mechanisms to understand and detect neural patterns of diseases and to modulate and control these neural patterns instead of pharmacological treatments. Electrical stimulation has been established over the past 60 years for excitation of nerves, but it has the disadvantage of limited spatial and fiber selectivity. Focused ultrasound as a stimulation modality for selective excitation of deep fiber ensembles in peripheral and autonomic nerves is the subject of research. Challenges include not only the development of miniaturized piezoelectric (PMUT) and capacitive (CMUT) ultrasound transducers, but also the packaging required for chronic implantation scenarios. Adhesion of packaging materials is key to reliability and longevity of implantable transducers. Polydimethylsiloxane (PDMS) serves as base material. Simulation models of the interfaces between PDMS and PMUT and CMUT arrays have been established to determine the shear and normal force distribution over the transducers. Silicon-based adhesion materials have been identified and tested under saline working conditions. Acoustic fields were measured and probe material interfaces were examined using microscopy. Initial results will be discussed in terms of material combinations and manufacturing processes.
