A Designer's Guide to Rapid Prototyping of Capacitive Sensors on any Surface
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Published in Planet Analog (http://www.planetanalog.com)
A Designer's Guide to Rapid Prototyping of Capacitive Sensors on Any Surface
By (Mark Lee, Senior Application Engineer, Cypress Semiconductor Corp.)
This article will discuss how to replace the mechanical buttons on a product with a smooth and sleek touch-sensitive surface.
It will present the concept of prototyping capacitive sensors on any nonconductive surface using silver-ink pens and copper
tape. Topics included are capacitive sensor basics, silver-ink and copper tape, and construction technique. Measured results
are presented for sensors applied to the back side of a simple acrylic sheet.
Capacitive sensing provides consumers a cool new way to interact with their MP3 players and mobile phones. Touch sensors
are hidden below the surface, so the area normally covered with the uneven features of mechanical buttons now look clean
and uncluttered. An effortless finger touch accesses product features that are usually controlled by the click of mechanical
buttons. To encourage experimentation with this new technology, this article presents a designer's guide to rapid prototyping
of capacitive sensors on any nonconductive surface.
Alternatives to PCBs and Flex Circuits
Imagine that you have a great idea for a product that includes a plastic injection-molded case or a glass panel, and you would
like to explore the possibility of replacing the mechanical buttons with capacitance sensors buried under the surface. The first
step in making a capacitive sensing system is to arrange a set of conductors on a nonconductive surface . The traditional
approach to implementing the sensors is to create a printed circuit or a flex circuit, but this can be time consuming, and may
not fit within your budget for a prototyping effort. How can you avoid the time and expense associated with traditional