Capacitive touchscreens work by using your body's natural electrical conductivity.

Capacitive touch technology relies on the principle of electrical capacitance to function. The screen consists of an insulator, such as glass, coated with a transparent conductor like Indium Tin Oxide (ITO). A constant grid of electrical charge is maintained across this surface. When a conductive object like a human finger touches the screen, it creates a distortion in the screen's electrostatic field.This interaction occurs because the human body is composed of approximately 60% water and various electrolytes, making it an excellent conductor. As the finger approaches, it acts as a second capacitor plate, drawing a minute amount of current to the point of contact. This results in a measurable drop in capacitance at that specific intersection of the grid.The device's controller processes these changes by scanning the X and Y axes of the screen thousands of times per second. This technology was first developed in the 1960s by E.A. Johnson at the Royal Radar Establishment in the United Kingdom. It differs from older resistive screens, which required physical pressure to push two layers together. Today, multi-touch capacitive sensors can track up to ten different points of contact simultaneously with sub-millimeter precision.