What is Touch Sensor,How it Works.

Touch sensors: What it is, How it works👍

By- Nitish Tech

Touch sensor has been common nowadays for displays and IoT projects with Arduino. They can be found in lamps, touch screens of smartphones, and other wide arrays of applications as well. However, do you understand the working principle of a touch sensor and how to use it alongside your Arduino?

Well, in this touch sensor guide, I’ll be covering the following to help you better understand Arduino and touch sensor by covering:

What is a touch sensor

How does a touch sensor work

Touch sensor applications

Types of touch sensor

List of touch sensor recommendations

How to use touch sensor with Arduino

What is a touch sensor?

A touch sensor is an electronic sensor used in detecting and recording physical touch. Also known as tactile sensors, it’s a small, simple, low-cost sensor made to replace old mechanical switches we seen in the past.

How does touch sensor work?

A touch sensor works like a switch, where when there’s contact, touch, or pressure on the surface of a touch sensor, it opens up an electrical circuit and allows currents to flow through it.

What is touch sensor used for? Key Applications

What is touch sensor used for? Key Applications

As mentioned in my introduction, a touch sensor is used for a wide array of applications, with those being:

Touch sensor in robotics; a touch sensor is commonly used in robots, enabling basic movement and the ability to detect touch in its surroundings (E.g. When the robot runs into something, the touch sensor can have it to stop moving)

Smartphones, automotive, industrial applications

Touch sensor faucet in kitchens; allowing for control of running water without having to physically turn the knob

Most other applications that require pressure/distance measurement

Types of touch sensor

The above explanations of how a touch sensor work and its applications apply to a generic sensor, where there are still different type of touch sensor that works uniquely and is more applicable for certain applications. Hence, I’ll be introducing the two main touch sensor types with its working principle/usages!

Capacitive touch sensor

Commonly associated with MicroChip at42qt1010, a Capacitive touch sensor measures touch based on electrical disturbance from a change in capacitance. It consists of an electrode film on top of the glass panel that’s conductively coated with a printed circuit pattern around the outer viewing area.

How capacitive touch sensor work:

The user applies touch on the glass panel

The printed circuit panel around the outer viewing area of the glass panel creates an electrical charge across the surface

It results in a decrease in capacitance and allows the system to determine the touch point

Multiple touchpoints can be detected as well, allowing for touch pinch and spread

Capacitive touch sensor applications:

•Portable devices  such as smartphones and tablets (iPhones, iPad, etc.)

•Home applications such as touch lamps

•Automotives

•Industrial

Resistive touch sensor

Resistive touch sensor measures touch through responding to the pressure applied to their surface. It consists of two conductive layers and a non-conductive separator. Unlike the capacitive touch sensors, it’s not multi-touch compatible.

How resistive touch sensor work:

The user applies pressure against the surface

The outside conductive layer is then pressed against the inner layer, resulting in voltage changes

The voltage changes are then compared to the starting voltage, allowing for the point at which the touch took place to be calculated