Guide

3
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Bend Sensor
®
Mechanical Application Guide
Introduction
This Application Guide is designed to help mechanical designers build interfaces that result in the
successful integration of Bend Sensor
®
components into products. Flexpoint Sensor Systems
(Flexpoint) has successfully developed and marketed products incorporating Bend Sensor
®
technology. As described below the Bend Sensor
®
device is typically a film – the Bend Sensor
®
film
is put into a system and essentially “goes along for the ride”. The film is attached to a system and
measures the movement of the system. Although the sensor itself is capable of being cycled millions
of times, the system it is applied to must also be robust. Below is a description of the sensor, and
many of the considerations that should be understood in the design of the system.
Description of the Bend Sensor
®
Device
The Bend Sensor
®
potentiometer is a product consisting of a plastic substrate coated with a resistive
material that changes in electrical conductivity as it is bent. Electronic systems can connect to the
sensor and measure with fine detail the amount of bending or movement that occurs. Depending on
the configuration and integration of the sensor resistance changes of greater than 10 times can be
realized. Refer to the Bend Sensor
®
Electronic Design Guide (http://www.flexpoint.com/wp-
content/uploads/2015/05/electronicDesignGuide.pdf) for a description of electronic interfaces.
An example application is one where a sensor is attached to a hinge. As the door is opened, among
other things one can measure how far the door is opened and how fast it is moving. The sensor is
lightweight, small, easily packaged and very reliable. The breadth of the application for the Bend
Sensor
®
device is limited only by the customer’s imagination.
Deflection of the sensor may be
achieved through many mechanical
options.
0
50
100
150
200
250
dA
dB
dC
dD
dE
dA
dB
dE
Film Layer coated
w/sensor material
Deflection
Resistance (k ohms) vs. Deflection of Sensor
R
e
s
i
t
a
n
c
e
s
The rate of change as displayed in the graph is dependent on two factors. The first is the bend
radius, the smaller the radius the greater the change. Secondly is the angular deflection. For a given
radius the more the sensor is bent around it the greater the change.