A wirelessly powered temperature sensor for cell culture micro system

This paper presents a wireless temperature sensor for the cancer cell culture on ITO glass substrate. In order to measure the multi-point temperatures in the biochip, the sensor chip is not only a wireless temperature transmitter but also wirelessly powered. This wireless temperature sensor uses a standard TSMC 0.18 µm 1P6M CMOS technology. The measured reference voltage of bandgap voltage reference circuit is 902 mV with a temperature-coefficient of 7.75ppm/°C from 0°C to 100 °C at a supply voltage of 1.8V. This circuit adopts a rail-to-rail differential difference amplifier (RRDDA) to scale the output voltage of the IPTAT from 25 °C to 100°C. In addition, it is measured with an 81.81dB differential gain stage for alleviating the common power noise from wireless power. The temperature-to-voltage is 0.01 V/°C. The feedforward voltage attenuation V-I converter (FFVA) will provide a high linear V-to-I of 840uA/V to the following ring oscillator over a wide input control range. The current-to-frequency of the VCO is 1.49 GHz/mA from 1G to 2.4GHz. The temperature-to-frequency of the whole chip is simulated to be 5.15 MHz/°C with a power consumption of 23.7 mW.