Capacitive Multi-Touch Sensor Prototyping Techniques

Rapidly prototype customized capacitive multi-touch sensors with this Arduino-based kit.

Jeremy S. Cook
3 months agoDisplays

As noted in this project’s research paper, “Mutual capacitance-based multi-touch sensing is now a ubiq­uitous and high-fidelity input technology. However, due to the complexity of electrical and signal processing requirements, it remains very challenging to create interface prototypes with custom-designed multi-touch input surfaces.”

In other words, while you might use a single capacitive sensor to replace a button in your next Arduino Project, creating a complex matrix such as the one used to interface with a smartphone is generally out of reach for those without extensive electrical engineering knowledge.

For the rest of us, researchers across several universities have been working on the amply named: "Multi-Touch Kit." This technique allows makers to use an Arduino boards or other similar hardware to take in multi-touch capacitive signals on sensing grids made with a variety of materials, and of different sizes and even shapes.

An Arduino firmware library, as well as a Processing library and an API form the “tools” used, along with the OpenCV library to determine finger positions. These techniques have been tested in various setups — a conductive 16x16 electrode matrix, measuring in at 177x177mm; on conductive yarn; and even on electrodes arranged on a 3D-printed rabbit. Hardware used includes an Arduino Uno, Mega, and LillyPad.

Jeremy S. Cook
Engineer, maker of random contraptions, love learning about tech. Write for various publications, including Hackster!
Related articles
Sponsored articles
Related articles