Adafruit Conductive Rubber Cord Stretch Sensor + extras! - 3m long

Measuring stretch forces becomes straightforward with conductive rubber cord. This 2mm diameter, 3-meter-long cord is crafted from carbon-black impregnated rubber. Initially designed for EMF gasketing, it doubles up as an intriguing tool for various experiments.

In its resting state, the cord's resistance is approximately 350 ohms per inch. Stretch it, and the resistance escalates as particles disperse. For instance, a 6-inch piece holds around 2.1 Kohms, and stretching it to 10 inches increases resistance to about 3.5 Kohms.

The rubber can stretch 50-70% beyond its resting length, ensuring it remains functional up to roughly 10 inches for a 6-inch piece. While returning to its original form isn’t instantaneous, the cord resumes its length in a minute or two after being stretched.

Though not precisely linear and varying slightly between batches, this cord effectively measures stretching motion. It includes three meters of rubber, two alligator clips for connectivity, and a 10K resistor, facilitating the creation of a simple voltage divider. Check our Thermistor tutorial to transform analog voltage into resistance.