You may be surprised how dependent you are on touch sensors in your daily life. If you have a smart phone, smart watch, or wireless earbuds, you could be interacting with touch sensors for more hours than you sleep! Plus, designing these touch sensors into devices comes with a number of challenges. This paper will discuss four challenges you might find when designing touch sensors, as well as possible solutions to these challenges.
A touch sensor is a device that captures and records a physical touch, typically from a human finger. The two main types of sensing technology are capacitive and resistive:
Capacitive sensors use the electrical properties of the human body as input and detect differences in capacitance caused by a human finger when it is in close proximity to the sensor.
Resistive sensors measure changes in electrical resistance caused by the application of force.
Generally, capacitive sensing has more advantages over resistive sensing and is thus more popular. Compared to resistive sensing, capacitive sensing solutions are more durable and do not suffer wear and tear. Capacitive sensing also allows for multi-point input operation; resistive does not. Capacitive sensing screens also generally have an improved picture clarity over their resistive sensing counterparts.
For these reasons, we'll be focusing on capacitive sensing when diving into the design challenges that designers face.
Author: Vibheesh Bharathan, Principal Systems Engineer, IoT Compute and Wireless at Infineon Technologies
Vibheesh Bharathan is a dynamic marketeer with strong engineering background in system design and semiconductor fields. Vibheesh Bharathan is a Product Marketing Manager responsible for Touch sensing technology portfolio of MCU product line at Infineon Technologies AG. He has over 15 years of experience in technical and business roles and enjoys technology and business development.