Touch Sensor

A touch sensor acts as a variable resistor as per the location where it is touched. The figure is as shown below.

A touch sensor is made of:

Ø   Fully conductive substance such as copper

Ø   Insulated spacing material such as foam or plastic

Ø   Partially conductive material

Principle and Working

The partially conductive material opposes the flow of current. The main principle of the linear position sensor is that the current flow is more opposed when the length of this material that must be travelled by the current is more. As a result, the resistance of the material is varied by changing the position at which it makes contact with the fully conductive material.

Generally, softwares are interfaced to the touch sensors. In such a case, a memory is being offered by the software. They can memorize the ‘last touched position’ when the sensor is deactivated. They can memorize the ‘first touched position’ once the sensor gets activated and understand all the values related to it. This act is similar to how one moves the mouse and locates it at the other end of mouse pad in order to move the cursor to the far side of the screen.

Applications

The touch sensors being cost effective and durable are used in many applications such as

·        Commercial – Medical, vending, Fitness and gaming

·        Appliances – Oven, Washing machine/dryers, dishwashers, refrigerators

·        Transportation – Cockpit fabrication and streamlining control among the vehicle manufacturers

·        Fluid level sensors

·        Industrial Automation – Position and liquid level sensing, human touch control in automation applications

·        Consumer Electronics – Provides a new feel and level of control in various consumer products