Hearing light when shone on MEMS microphones?

Log In to Reply

Curiosity Science Physics Hearing light when shone on MEMS microphones?

Tagged: ,

  • In this video, James did an experiment in which he shone a modulated high-powered blue light laser at the MEMS microphone of an iPhone. This created a buzzing noise. We attempted to recreate the experiment using He-Ne laser and green light laser. However, no sound was picked up by our phone. Could someone please explain how the phone being shone at was set up? What additional factors may impact of this experiment? If the result in the experiment was caused by photoelectric effect, then could it be that the frequency of our laser simply isn’t enough to trigger said effect. Working on a deadline for science fair. Any recommendations would be greatly appreciated.

  • Hi! This is very interesting. Maybe it’s not photoelectric effect at all. Could it be because of the thermal effects? Try playing with the intensity of the laser perhaps. Also, how are you generating the frequency? And maybe the other factor could the phone itself. The laser could be aimed at the hole where you assume the mic is, but on some smartphones, the mic is placed at an angle to avoid accidental damage—like when someone uses the mic hole to eject the SIM tray instead.

    Smartphone mic placed at an angle

    Image credit – Dominik Schnabelrauch under CC BY-NC-SA.

You must be logged in to reply to this topic. Log In