Development of an implantable micro temperature sensor fabricated on the capillary for biomedical and microfluidic monitoring

An implantable micro temperature sensor has been designed and fabricated on a capillary with only 300μm outside diameter by surface micromachining. The transient temperature distribution of the sensor used in the hyperthermia is simulated and analyzed. The temperature sensor has been successfully fabricated by our previously developed cylindrical projection lithography system. Magnetron-sputtering platinum film and lift-off processes are mainly used to realize the temperature sensing element. The temperature coefficient of resistance (TCR) and the current-voltage (I-V) curves of the temperature sensor prototype have been tested and evaluated. The test average TCR value derived from the fitted line is 0.00384/°C, which has a good agreement with industry standard value of the bulk platinum resistor. The present micro temperature sensor could be widely used as an important implantable monitoring device in several biomedical and microfluidic applications, especially in the hyperthermia.