Ultrasonic Energy Harvesting Scheme for Implantable Active Stent

In this paper, we report an ultrasonic energy harvesting scheme that will provide a powering platform for percutaneous coronary intervention (PCI), named Autonomous Active Stent (AAS). The AAS harvests energy from ultrasound and powers a range of embedded sensor and electronics. This technique is expected to change the paradigm of current PCI by not only replacing the bare wire stent but also monitoring and preventing the failure. The device consists of 50μm-thick polyvinylidene fluoride (PVDF) with various surface patterns. The patterns were designed to allow expansion. The pattern also helps the AAS to induce an increase in surface vibration, which overall contributing higher power efficiency. The AAS with closely placed surface patterns exhibited higher output (14.8% improvement as compared to the plain PVDF). The AAS (3cm length, 1cm diameter) was able to generate 230μW of electrical power with an efficiency of 11.5% when it was exposed to 14MHz ultrasonic wave.