1. EMI-EC410502 Flex Sensor Electronics & Communication
Department 9/27/2014 Flex Sensor
2. 1 Vatsal Shah Indus University Flex Sensor A Seminar Report
On Flex Sensor Vatsal Shah Electronics and Communication
Engineering Department 5th Semester IU1241090055 Indus Institute of
Technology and Engineering Submitted to:- Submitted by:- Ankur
Rathi Vatsal Shah. Asst. Prof. EC Dept.
3. 2 Vatsal Shah Indus University Flex Sensor Contents 1.0
Theoretical
background...............................................................................................3
2.0
Schematics....................................................................................................................4
3.0 How they
Work?............................................................................................................5
4.0 Simulation and results
.................................................................................................6
5.0 Electrical
Characteristics.............................................................................................7
6.0
Problems........................................................................................................................7
7.0
Application.....................................................................................................................8
8.0 Project
............................................................................................................................9
9.0
Reference.....................................................................................................................
10
4. 3 Vatsal Shah Indus University Flex Sensor 1.0 Theoretical
background A Flex and Force sensor. This is a flexible sensor which
changes its output when it is bent or when force is applied on it.
This sensor has two output wires. The resistance between these two
wires varies when the sensor is bent or when subjected to a force.
Hence, this sensor can be used as a flex or force sensor. When the
sensor is kept straight with no force acting on it, it has a
resistance of around 10 K Ohms. When the sensor is bent in either
way, or when force is applied on the sensor, the resistance between
these two wires increases proportionally to the amount of bending.
They convert the change in bend to electrical resistance - the more
the bend, the more the resistance value. They are usually in the
form of a thin strip from 1"-5" long that vary in resistance from
approximately 10 to 50 K ohms.
5. 4 Vatsal Shah Indus University Flex Sensor 2.0 Schematics
Flex Sensor as Voltage Divider - Output voltage increases with the
bend. The impedance buffer in the circuit reduces error due to
source impedance of the flex sensor as voltage divider. Suggested
op amps are the LM358 or LM324. We can also test our flex sensor
using simple test, and skip op-amp.
6. 5 Vatsal Shah Indus University Flex Sensor 3.0 How they
Work? Flex sensors are analog resistors. They work as variable
analog voltage dividers. Inside the flex sensor are carbon
resistive elements within a thin flexible substrate. When the
substrate is bent the sensor produces a resistance output relative
to the bend radius. With a typical flex sensor, a flex of 0 degrees
will give 10K resistance will a flex of 90 will give 30-40 K ohms.
The Bend Sensor lists resistance of 30-250 K ohms. .
7. 6 Vatsal Shah Indus University Flex Sensor 4.0 Simulation
and results0.51.52.5 9 14 19 24 Voltage(V) Resistance (Kohm)
Voltage vs Resistance
8. 7 Vatsal Shah Indus University Flex Sensor 5.0 Electrical
Characteristics Size: approx. 0.28" wide and 1"/3"/5" long
Resistance Range:1.5-40K Temperature Range: -35 to +80C Voltage: 5
to 12 V 6.0 Problems Only one working flex sensor Reduced accuracy
to differentiate between gestures Broke due to heat
9. 8 Vatsal Shah Indus University Flex Sensor 7.0 Application
The Bend Sensor technology has many potential applications in the
consumer products sector. A key marketing strategy is to pursue
product applications that emphasize functionality, reliability,
quality, and user convenience. Such products might include computer
peripherals (mouse, key board, controllers, input devices, laptop
controls, etc.), communications equipment (cellular phones), small
and large appliances (high temperature switches, safety controls,
on/off switches, balance controls). Toys o In 1998, the Company
produced over 7,000,000 Bend Sensors for incorporation into several
lines of interactive plush toys. Auto Control Fitness Products
Gaming Glove Medical o In the medical product area, such
applications might include infusion pumps, respiratory therapy
equipment, obstetric equipment, rehabilitative and physical therapy
equipment, pelvic stabilization devices, Pressure-Monitoring
Devices, etc. Horn Switch o The Flex point sensor is a thin sheet
of screen-printed plastic that can be laminated between the air bag
assembly and a flexible cover on the steering wheel. The device can
be placed over the air bag assembly on the steering wheel in place
of the traditional switch that has been placed on the side of the
air bag assembly, thus eliminating the frustration and design waste
associated with the need for button switches.
10. 9 Vatsal Shah Indus University Flex Sensor 8.0 Project The
parts required: Arduino UNO 10 x Red LEDs 9 x 330 Ohm resistors for
the LEDs 1 x 10K Ohm resistors for the flex sensor. 1 x Flex sensor
Wires and Breadboard to connect it all together
