Photochemically Patterned Biliary Stents with Integrated Permanent Magnets and Deformable Assembly Features for Wireless Magnetoelastic Tissue Growth Sensing

Sludge accumulation in biliary stents causes a loss of patency, leading to complications such as jaundice. We report batch-fabricated biliary stents with integrated magnetoelastic sensors for monitoring tissue growth. Integrated neodymium magnets bias the sensor and remove a source of measurement error. Paraffin mass loads up to 44.2 mg simulated tissue growth on 37.5times2 mm², 28 mum thick sensors. A resonant frequency shift from 58.81 kHz to 34.42 kHz was observed. The sensor provides a usable signal to the interrogation system if present within at least a 320 cm³ volume adjacent to the interrogation coils.