Step 1: Design Principle
With 60mW of high efficiency cat-like night vision, you could reduce your carbon footprint by using less electricity. You'll need less of your high powered indoor lighting. And by reading more, you'll reduce the electricity consumed by your TV and your computer. By being a bookworm, you'll burn less calories and need less food, which will drive down the global price of food. In time, Zimbabweans may be able to buy more than one egg with Z$50 billion. This could be the solution to all the world's problems. I just hope it catches on in time. ;)
Step 2: What Is It?
So what you need are:
a piece of foam board, approx 1 3/8" x 3 3/4"
a soft, white, LED with wide angle Lambertian dispersion pattern
a toggle switch
a small lipoly battery
a 20 ohm resistor
a heat gun
a glue gun
wire, solder, soldering iron
a baseball cap
Step 3: Body
This will provide the structure upon which the light is built. The right stuff for this job is 3mm thick PVC foam board. The stuff I used goes by the tradename of Sintra.
The main reason I'm using PVC foam board is because it's easy to cut and heat-form. It's also very light.
So here's how you do it. Cut out a 1 3/8" by 3 3/4" rectangle, or thereabouts. Heat it over a heat gun until it gets floppy. Then fold it in half and press it around the brim of your hat.
Here's a video:
Step 4: Power
Well, I happened to have a very small lipoly battery lying around. I lost my bluetooth headset the other week, and I later found it smashed up in the parking lot where I must have dropped it. It was beyond repair, so I salvaged the battery.
If you want a battery like this without waiting for your bluetooth headset to break, sometimes you can find replacement batteries for mini RC helicopters. Here is a pair of similar batteries I just happened to spy on Ebay:
Another way to do it would be to buy a cheap bluetooth headset ($10.00 and up) and convert it to a banana-phone (or maybe stick it into the frame of a comfortable corded external headset). And while you're at it, change the battery out for one of the larger batteries from your stockpile. That's how I got my second battery, which I used to make this Instructable.
Step 5: LED
So with this LED I soldered the resistor right onto the heat sink, then glued it in place. It's pretty self-explanatory.
Step 6: Switch
Step 7: Done
Here's a video demonstrating the grip. It's impressive! This light will never accidentally fall in the toilet, unless it's accompanied by the rest of the hat. :)