Stretch Sensor

Initial report by Hsiao-Ho Hsu, Oct. 3 2005

The Merlin Stretch Sensor is a new way to measure stretch, displacement, compression and force.It is a flexible cylindrical cord with spade electrical fixings at each end. The sensor behaves like a variable resistor, the more you stretch it the higher the resistance.

Applications

Stretch Sensor can act like muscle contraction, and can be easily applied to any wearable design.

Electrical Characteristics

datasheet here

A fresh 19 cm stretch sensor gives out 5k Ohms when resting, 22k Ohms when fully stretch(appox 40 cm)
A kinda-old 21.5 cm stretch sensor gives out 13.5K Ohms when resting, 60kOhms when fully stretch(appox 55cm)

Pin Descriptions

It acts like a variable resistant, just plug one into the ground and another into pic.

Microcontroller Connections

Code Sample

Stretch Sensor use raw data in
Stretch Sensor with an amp bridge

Typical Behavior

According from data sheet, as the length of the Stretch Sensor alters so does it's resistance. For each centimeter of length change there is a resistance change of approximatly 400 Ohms/cm.

Application Notes

Since stretch sensor is made by rubber, it gets loose and increase the resistance after a certain time.
http://notsimplyyes.com/SW/datasheetreading.htm