Richard Lippmann's 3D-Printed Switch Adds Push-to-Light LEDs to Any Greetings Card

Maker Richard Lippmann has designed a 3D-printable part which, when combined with a coin-cell battery and some conductive tape, lets you build your own light-up greetings cards —for a fraction of the cost of off-the-shelf equivalents.

"This card switch makes it easy to add LEDs that light up when you press a spot on the front of a homemade card," Lippmann explains. "I found that other approaches using foam tape, paper, and glue are time consuming and sometimes unreliable. This single 3D-printed part snaps together with a CR2032 coin cell, two strips of conductive Faraday tape, and keeps working after 500+ presses."

The idea behind the project is simple: create a device that is thin and light enough to slip inside a folded greetings card and that will light up an LED when pushed. "It is a direct, lower cost alternative to commercial products like EZ-Lights," Lippmann explains of the the design, which he estimates costs under $2 in parts per card, "that can cost $10 or more."

The idea is simple: the 3D-printed switch, with optional "push" labeled button, hovers the battery over conductive tape typically used to create "Faraday pouches." Squeeze, and the frame compresses to bring the battery into contact with the tape — completing a circuit that leads to a bright LED.

"To light multiple LEDs," Lippmann advises, "connect them all in parallel: all positive LED leads go to the positive tape, all negative leads go to the negative tape. Use LEDs of the same blue or white color for consistent brightness. You can expect good performance with up to 5–10 LEDs of the same color in an occasionally-used card."

Lippmann's full tutorial is available on Instructables, with print files published to Maker World under the reciprocal Creative Commons Attribution-NonCommercial-ShareAlike license.