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 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!