Microprotrusion Decorated Solid Coupling for Long-Term Wearable Ultrasound Monitoring

Wearable ultrasound technology especially piezoelectric micromachined ultrasonic transducers (PMUTs) has great potential to realize long-term wearable health monitoring. This work presents mount microprotrusions on planar solid film (MPoPSF) to couple PMUT and skin. The MPoPSFs with different protrusion shapes and densities were designed based on the skin feature and fabricated by silicone molding technique. It was bonded to the surface of PMUT with center frequency being ~8MHz. The MPoPSF bonded to PMUT was pressed on artificial skin with a blood vessel to make solid coupled ultrasound measurement. Experiment indicated MPoPSF enhances the ultrasound signal and an improvement of over 15% was achieved using MPoPSF. This study opens an avenue to develop solid coupling strategy to PMUTs for convenient long-term wearable ultrasonic monitoring.