What touch pads sense is heat and pressure. For example, if you place a pen on the touch pad of a laptop or other computer, it will not do anything but if you touch it with your finger, it will work.
touchpads are most found on notebook computers!
in 1980
keyboard, mouse, touchpads, external storage devices( including cameras etc...) is that what you are looking for?
Logitechs sell those type of keyboards.
IR sensors
Alot of them use a sonar-like sensors that emit soundwaves to help them "see".
Exploratory robots use motion, heat, and camera sensors.
the fork on the left
buy
All snakes use heat sensors, they use them to find food, a shelter and what things are.
The same sensors Air France uses on theirs.
At 1GHz single core, it isn't quite keeping up with the highest quality phones at the moment.The touchpads can be tricky to get used to using as analogue sticks.Most apps aren't optimised to use the touchpads (although many are, and almost all can use the other hardware controls)Battery life is mediocre. Better than the average android phone, but you will still run out of charge after 6 hours of gaming or 2 days of light use.