Robust implantable blood pressure sensor packaging for long-term laboratory animals monitoring

摘要

A robust implantable blood pressure sensor packaging technique is demonstrated for long-term laboratory animals monitoring. The packaged sensors achieve a lifetime over 100 days in PBS solution at 37 °C, adequate for the proposed implantable application for life sciences research. The proposed packaging technique employs a multi-layer of Parylene and PDMS coating over a MEMS piezoresistive pressure sensor, thus effectively slowing down the moisture penetration and electrochemical etching of the metal traces on sensor surface or PCB surface under a bias condition. Further analysis of experimental results reveals a strong relationship between lifetime of packaged sensors and bias voltage level, suggesting a design trade-off between system sensitivity and reliability.