Conductak Business Card Flashlight!




Introduction: Conductak Business Card Flashlight!

About: Conductak is a conductive sticky tack. Use it to stick circuits anywhere!

If you've been to an event such as the 2015 Bay Area Maker Faire or the Santa Monica Proof of Concept Innovation Fair, you may have picked up a business card from Conductak, the conductive sticky tack. The back of the card has a mysterious diagram with a link to the Conductak Instructables page. What's it for!? Well, with a few parts and some Conductak you can make your card into a handy touch activated flashlight!

Step 1: Materials

To make the Conductak business card flashlight, you'll need:

x1 Conductak business card

x1 Paperclip

x1 NPN transistor

x1 LED (whatever color you'd like)

x2 Conductak pellets

x2 Lithium coin cell batteries

x1 5.5" copper foil tape (1/8" - 1/4")

Step 2: Attach LED

To make sure you don't run out of Conductak halfway through the build, I recommend splitting the pellets into thirds. Cut the copper foil tape into lengths that will more or less fit the lines on the card. Place the tape on the card.

Bend the legs of the LED straight outward, keeping track of the positive and negative legs (the positive leg is longer). Place the LED to the end of the card as shown, matching the LED's polarity with the markings on the diagram. Split one of the Conductak pellet thirds in half and use the two pieces to stick the LED to the copper foil tape.

Step 3: Attach Transistor and Batteries

Halve two more of the thirds (fractions!). Use three of the pieces to stick the transistor on the copper foil tape, with the transistor's body facing the same way as the diagram.

You can roll up the remaining Conductak together and divide it into four equal pieces. Use two of the pieces to stick the coin cell batteries to the copper foil tape, matching the polarity on the diagram. Use the last two pieces of Conductak to stick the paperclip across the tops of the two batteries.

Step 4: Use It!

To use your flashlight, touch the circle labeled on the diagram as "Touch-On". The conductivity of your skin allows enough current to flow to the base of the transistor to turn on the LED! Your flashlight probably won't hold up in a purse, but the glove box of your car or a desk drawer would be a fine place to store this handy light!



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    11 Discussions

    Thanks for the comment, Kiteman! Yup, hopefully I'll be selling Conductak later this year. Right now I make it on a hand cranked mill, so I'm trying to get access to a mixing machine (and non-toxic certification).

    Sugru started on that sort of scale - you could try asking them for advice on how to get through that stage.

    why not just use hot glue to coat the whole thing(besides the batteries?
    considering hot glue isnt conductive it would make it more stable right?

    1 reply

    If you're looking for something more permanent, then yes! The business card light is designed to be more of a novelty than anything else, so it's expected that you'd eventually disassemble it and reuse the tack and parts for other projects. If you wanted to though, you could definitely coat the components with a hot glue or epoxy to seal them on. I'd probably add a ~1M resistor from gnd to the transistor base as well, to make sure the light is totally off when not in use. The circuit as shown errs on the side of simplicity rather than functionality.


    3 years ago

    I don't get it. Cellophane tape would do pretty much the same job here. Just move the paperclip to the surface contacts of the batteries.

    1 reply

    Hi thuzil, thanks for the comment! Taping components down often leads to poor electrical connections, which can be incredibly frustrating to troubleshoot (especially in a classroom/workshop environment!). I welcome you to recreate the circuit using regular tape. If it works for you, that's awesome! But if you get stuck with a finicky flickering LED, I welcome you to follow Conductak on Twitter, Facebook, or sign up for the mailing list on :)

    Hi tomatoskins, sorry for the late reply! I'm hoping to make Conductak commercially available within the next couple of months. You can follow Conductak on Twitter or Facebook or sign up for the mailing list on the website, to find out as soon as it happens!