Why do some electric artifacts (as a laptop, for example) feel “electrostatic” when you glide your finger across their surface?

Question

It doesn’t feel like a shock or anything like that, it feels like a slight vibration under my fingertip.

In: Physics

Answer 1

It’s hard to know exactly what sensation you are describing but here are some possible explanations:

1- you are actually feeling a current. If the laptop has a grounding problem and there is a voltage difference between you and the laptop surface you could experience some current flow through your finger especially if it’s moist. This doesn’t explain why this would happen when running your finger however.

2- friction. Depending on the materials the pressure you apply and the texture of your skin, running your finger can cause the skin to vibrate, which can cause a sensation you describe.

3- in combination with 2, if your laptop had rotating parts such as hardrives or fans, it can produce its own vibration which resonates when your run your finger on a surface.