Ultra Low Power CMOS-Based Sensor for On-Body Radiation Dose Measurements

For the first time, a dosimeter employing two floating gate radiation field effect transistors (FGRADFET) and operating at mere 0.1 V is presented. The novel dosimeter requires no power during irradiation and consumes only 1 during readout. Besides the low power operation, structural changes at the device level have enhanced the sensitivity of the dosimeter considerably as compared to previous designs. The dosimeter is integrated with a wireless transmitter chip, thus eliminating all unwanted communication and power cables. It has been realized monolithically in DALSA's 0.8 complementary metal-oxide-semiconductor process and characterized with X-ray and γ-ray sources. A maximum sensitivity of 5 mV/rad for X-rays and 1.1 mV/rad for -rays have been achieved in measurements. Due to its small size, low-power, and wireless operation, the design is highly suitable for miniaturized, wearable, and battery operated dosimeters intended for radiotherapy and space applications.