A TeraMOS sensor based on a CMOS-SOI-MEMS transistor, thermally isolated by the MEMS post-processing, designed specifically for the detection of THz radiation which may be directly integrated with the CMOS-SOI readout circuitry, in order to achieve a breakthrough in performance and cost. The TeraMOS sensor provides a low-cost, high performance THz passive or active imaging system (roughly in the range of 0.5-1.5 THz) by combining several leading technologies: Complementary Metal Oxide Semiconductor (CMOS)-Silicon on Insulator (SOI), Micro Electro Mechanical Systems (MEMS) and photonics. An array of TeraMOS sensors, integrated with readout circuitry and driving and supporting circuitry provides a monolithic focal plane array or imager. This imager is designed in a commercial CMOS-SOI Fab and the MEMS micromachining is provided as post-processing step in order to reduce cost. Thus the CMOS transistors and technology provide the sensors as well as the signal processing and additional readout circuitry both in the pixels as well as around the sensor array.