Ultra-fast and high resolution NEMS thermal detector based on a nano-air-gap piezoelectric resonant structure

摘要: This paper presents the theoretical modeling and experimental verification of an innovative Nano Electro Mechanical System (NEMS) technology suitable for implementation ultra-fast high resolution un-cooled thermal detectors. Fundamental challenges associated to mechanically resonant detectors are overcome with introduction platform in which a temperature sensitive Aluminum Nitride (AlN) nano-plate resonator monolithically integrated micromachined suspended heat absorbing element perfectly overlapped but separated by sub-micron air gap. By placing outside body (but over it) electromechanical performance device is not affected material employed implement it (quality factor, Q≈1800 coupling coefficient, k t 2≈1%) enabling use compact low-power self-sustained oscillator circuit as direct frequency readout. At same time, efficient quick transfer from nanomechanical achieved minimizing gap between them. The detection capabilities this first prototype were tested using resistive source lieu absorber. Power level low 655 nW was readily detected limit 48 experimentally extracted. In addition time constant ∼ 60 μs predicted through finite simulation.