This is an application of the "Tiny Wearable LED Kit" that I produced for the kit challenge recently. For details of the circuit, programing etc, please see this instructable
In this instructable, I am going to use some thin stainless steel wire to integrate the kit into a tie for father's day. Arguably this might be better done with conducting thread but I don't have any and the very thin wire works rather well.
You will need:
A made-up Tiny Wearable LED Kit from this instructable
12 ultra-bright blue LEDs (white, violet, UV or blue-green will also work. Don't choose red, orange or yellow*)
A made-made fibre tie (please don't use your dad's best silk tie - it's harder to make and he might not thank me too much)
Around 2m of thin stainless steel wire
Soldering iron & solder
M4 machine screw
Small vice grips
Heat source (blowtorch)
Small heat-proof scrap (e.g. small piece of tile)
Two small (1.5 x 2.5 cm) pieces of iron-on meding fabric (or ordinary fabric if you are prepared to do a bit more sewing)
self-amalgamating tape ( optional - few cms only)
* You could probably make these work with some small resistors but that's a dozen extra parts and I haven't tried it. See step 4 (LEDs) for speculation on resistor values.