Question: How is static electricity built up inside you?

Stefan Lines answered on 12 Nov 2014:

Good question! I hate static electricity, especially in the summer when you keep getting zapped by car doors.

It’s all thanks to something called the Triboelectric Effect. Generally speaking, people are neutrally charged – that is there is a balance between positive and negative charges. When you walk, you make contact with the floor. Depending on what you’re wearing and what you’re walking on, you can become either negatively or positively charged. That happens when you either lose or gain electrons.

For example, you might walk on a material that really wants electrons, and as you walk over it, you donate them. You then become positively charged. The other way is that the shoes you wear might want to receive electrons, and the floor gives them to you.

Either way, you’ve become charged either way – and remain so because you’re not earthed (charge can’t flow out of you or into you, via the ground). Typically this happens because of wearing rubber shoes. Anyway… when you go to touch something that is earth, charge either flows out or into you (depending on whether you’re positive or negative) into that object so that you can become neutral again. It happens fast, and causes that shock feeling.