Mechanical memory and tunable nano-electromechanical systems (NEMS) resonator

A method for photodetection of light with a nanoelectromechanical (NEMS) resonator, the method comprising:

• applying a gate voltage between the drum membrane and a back gate,
• exposing the membrane to laser light to produce photoionization of the drum membrane such that a resulting charge alters the membrane resonant frequency,
• turning off the laser light and releasing the gate voltage to set the resonant frequency of the membrane to a predetermined frequency;
• exposing the drum membrane to the light to produce photoionization of the drum membrane such that a resulting charge alters the membrane resonant frequency;
• measuring the drumhead resonance frequency and comparing it to the predetermined frequency to determine total accumulated exposure of the drumhead to the light.