Picked up a Flex Sensor from Jameco (150551).
This unit measure 10K when flat and up to 30-40K when
bent to 90 degress.
 Data sheet says it is from Images Company who has a WEB page
where they sell this and other robotic items. On back of unit it is
labled Abrams Gentile Entertainment patent 5.086.785.
It consists of a piece of mylar 4 inches by 1/4 inch with 2 terminals
on one end. One terminal is connected to a silver conductive strip. This is
covered with a strip of carbon resistance. On top of that are isolated silver
conductive squares with the last smaller one conneted to the other terminal.
 Price is $10 which seems a bit expensive for what it is but something
interesting\
to play with.