A stretch sensor is a sensor which can be used to measure deformation and stretching forces such as tension or

bending In applied mechanics, bending (also known as flexure) characterizes the behavior of a slender structural element subjected to an external load applied perpendicularly to a longitudinal axis of the element. The structural element is assumed to ...

. They are usually made from a material that is itself soft and stretchable. Most stretch sensors fall into one of three categories. The first type consists of an

electrical conductor In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge (electric current) in one or more directions. Materials made of metal are common electrical conductors. Electric current is gen ...

for which the

electrical resistance The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallel ...

changes (usually increases) substantially when the sensor is deformed. The second type consists of a

capacitor A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals. The effect of a ...

for which the

capacitance Capacitance is the capability of a material object or device to store electric charge. It is measured by the change in charge in response to a difference in electric potential, expressed as the ratio of those quantities. Commonly recognized a ...

changes under deformation. Known properties of the sensor can then be used to deduce the deformation from the resistance/capacitance. Both the rheostatic and capacitive types often take the form of a cord, tape, or mesh. The third type of sensor uses high performance piezoelectric systems in soft, flexible/stretchable formats for measuring signals using the capability of piezoelectric materials to interconvert mechanical and electrical forms of energy.

Applications

Wearable stretch sensors can be used for tasks such as measuring body posture or movement. in 2018, New Zealand based company StretchSense began making a

motion capture Motion capture (sometimes referred as mo-cap or mocap, for short) is the process of recording the movement of objects or people. It is used in military, entertainment, sports, medical applications, and for validation of computer vision and robo ...

glove ( data glove) using stretch sensors. Unlike gloves that use inertial or optical sensors, stretchable sensors do not suffer from drift or occlusion. They can also be used in

robotics Robotics is an interdisciplinarity, interdisciplinary branch of computer science and engineering. Robotics involves design, construction, operation, and use of robots. The goal of robotics is to design machines that can help and assist human ...

, particularly in soft robots.

References

{{Reflist Sensors Resistive components Measuring instruments Transducers

Applications

See also

References