Every time you touch a tablet you’re expending a little bit of energy… and so is your tablet as its battery slowly drains. But designers Yonggu Do and Eunha Seo have a vision for a tablet with a built-in piezoelectric film that could actually generate power every time you touch the screen so that you could go longer without having to plug in the tablet.
The EcoPad concept images depict a tablet that never needs to be plugged in at all, but I’ll believe that when I actually see it. After all, how would you watch a video or read a book or perform other activities which don’t require you to touch the screen very often?
On the other hand, a tablet that harnesses this kind of technology to at least prolong your battery life under some circumstances would certainly be pretty cool.
via SlashGear
Well, add heat dissipated by your hands and body when your tablet/phone is in your pocket, sun and you get fully mobile device that you wont have to recharge ever 😉 Its the future.
Just for s’s and g’s, here’s a little physics: Assume the tablet consumes 3W continuous. Now assume that every touch event deflects the piezo material by 1mm, the piezo material is 100% efficient at converting squeezes to electricity, and the user touches the screen once per second. How hard must the user press each time?
3 W = 3 J/s = F*d*1/s
rearranging, F = 3 J / d.
d = 0.001 m,
so F = 3000 N ( = 675 lbs force)
Better hit the gym for those finger lifts if you’re gonna run a tablet like this.
The big advantage to this would be in that you don’t have to flood the screen with electrons to detect the disturbance a finger or capacitive object makes when it disrupts that field. Â That right there would save power.
The thing is though that we have that technology, it’s called resistive touch.  So I’m not sure how well this tech will do with multi-touch, or how much users are going to want to press hard on a screen to generate the force required to dislodge electrons from the piezoelectric surface to generate a current.
And the concept of not having to charge it… Â Umm yeah, if you’re touching it enough to generate enough current to offset the drain from the screen backlight, the SOC, etc. then yeah. Â But that’s not the use model I’ve seen with tablets. Â Mostly you touch them a few times and then sit back and read or watch… Â Maybe in gaming, but then you’ve got the highest energy drain on the system going full bore, the gpu…