Detects bending, movement, vibration, humidity, and more
This simple sensor detects how much it is being bent. Its simplicity makes it versatile; it can be used to detect vibration, humidity, motion, impact, and air flow. For example, sew it into the arm of a stuffed animal to respond when a child moves the arm, or place it inside the tube of a medical device to monitor the velocity of air through the tube (the faster the air, the more the sensor will bend).
The bend sensor consists of a coated substrate, such as plastic, that changes in electrical conductivity as it is bent. This provides non-mechanical reliability in electronic sensing and actuator technology.
The sensor consists of a plastic film printed with a special carbon ink. The film is nothing unusual; the real innovation is the ink. The resistance of this ink decreases the more it is bent. The ink can be printed on virtually any custom shape and size film.
It is designed primarily for detecting relative change. Because the plastic is hydrophilic (it absorbs moisture), the flexibility of the film changes with humidity. If you wanted to use the sensor as a scale to measure absolute weight, you would need to calibrate before each use.
The bend sensor is self-contained and requires no mechanical components. It is not prone to degradation through mechanical contact, so it has a longer life than many competing sensors. The longer life of components means fewer system breakdowns due to mechanical failure; it is more reliable and less expensive.