Touch sensitive LED strip

Hi all, I'd like to create a touch sensitive LED strip, a bit like this - . Touching the LED strip makes the LEDs light up from the bottom to meet your finger. The LED strip is obviously easy to handle, but I'm not sure of the best way to detect the touch. I can't seem to find any transparent touch strips, an iPhone digitizer is transparent but way too big. Does anyone know if there's something similar to the iPhone digitizer but in a strip? or any other ideas on how to achieve this?

Thanks Dave

Most likely what Lutron did was have a custom made resistive touchscreen, so it’s the same technology used on something like a DS screen. Maybe you could use a proximity sensor to sense how far away your finger was?