Wireless vascular bioelectronic systems with printed soft sensors and flexible electronic stents

Implantable vascular sensors can offer advantageous alternatives to the existing invasive and repetitive procedures that provide incomplete views of vascular health. However, device manufacturability, alongside strict requirements of size, mechanics, and sensing capability, have hindered the development of implantable vascular sensors. Here, we report an implantable sensing system based upon an electronic vascular stent and printed soft sensors capable of monitoring a variety of hemodynamics and vascular conditions. Fabrication strategies, materials, and sensing designs are studied to create a flexible and miniaturized passive, wireless sensor compatible with conventional minimally invasive endovascular surgical procedures. Vascular medical stents are redesigned and a rotational laser-based micromachining process is optimized to create multi-material, 3D structures that mechanically serve as a medical stent while electronically acting as an inductor for passive sensing. Mechanical and electrical performance of the inductive stent is comprehensively characterized. Soft sensors are manufactured via multi-layered aerosol jet printing of silver nanoparticles and polymers before packaging with electronic stents. Sensing mechanisms and performance are studied to enable low-profile form factors and high sensitivity. The integrated stent and sensor system is wirelessly monitored by inductive coupling after implantation via catheter. Highlighting the adaptability of this implantable platform, we create different sets of sensing systems to target monitoring of pressure, flow, and arterial stiffness. In vitro studies demonstrate wireless sensing of vascular health. Collectively, the studies of device fabrication and sensor design provide promising strategies for vascular electronics.