Would a drop of sweat on a capacitive touchscreen be considered a touch?

Capacitive touch screens will (mostly) ignore drops of sweat because they are based on capacitance and not conductance, and a bead of sweat doesn't have much capacitance. Your body is a big capacitor - internally conductive with lots of free electrons surrounded by an insulative sack of skin. When your body encounters an electric field, electrons move within your body to wherever the field is the most positive, altering the electric field in the process. Capacitive touch screens can sense this change in the field. Small drops of sweat simply aren't big enough, don't have enough free electrons, don't have enough capacitance to trigger the screen. For proof, take a zucchini and try using it on a touch screen - it is fairly capacitive and will work. Then try moving a small piece of conductive metal on a touch screen using a wooden pencil. Despite its conductivity it won't register on the display. Now if your display is covered and sweat and you try to touch it, the sweat that is both touching the display and your finger will end up demonstrating the same amount of capacitance as your body, so sweat will mess up accuracy, but the beads of sweat themselves won't register as touches.

Sweat is an excellent conductor. If the touch-screen or touch-pad is sensitive to electrical conductivity alone, then a drop of sweat would be considered a touch. To prevent errors of this kind, many touch-pads (e.g. in Mac notebooks) use a combination of electrical and pressure sensitivity. ----------- .

maybe. if the software is REALLY good, however, a touch wont be declared unless and until a double CHANGE is detected. figure on, finger off, so to speak. a drop of sweat by itself doesn't cause two changes in a reasonable timeframe. there are subtleties involved in the basic problem though. have you ever heard of the spilled coffee test?

Sweat is an excellent conductor. If the touch-screen or touch-pad is sensitive to electrical conductivity alone, then a drop of sweat would be considered a touch. To prevent errors of this kind, many touch-pads (e.g. in Mac notebooks) use a combination of electrical and pressure sensitivity. ----------- .

maybe. if the software is REALLY good, however, a touch wont be declared unless and until a double CHANGE is detected. figure on, finger off, so to speak. a drop of sweat by itself doesn't cause two changes in a reasonable timeframe. there are subtleties involved in the basic problem though. have you ever heard of the spilled coffee test?