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Wearable Tech

FEATURE

earable

circuits don’t

necessarily have

to be complex. Keep

your project streamlined

and use the simplest circuit

you can. A simple circuit, implemented well, can have

a big impact. Most tutorials for wearables will use one

of these three common techniques. Learn them all, and

you’ll be able to choose the best option for your own

wearable designs.

PREMADE CIRCUITS

A quick and easy way to get started is to use a premade

circuit. Instead of building the circuit from scratch, you

can skip ahead to figuring out how to put it into your

garment. Fairy lights are great premade circuits, as most

come with a simple battery pack and a built-in power

switch. Another type of premade circuit is an all-in-

one board like Adafruit’s Circuit Playground Express, a

microcontroller with built-in lights and sensors.

When using premade circuits, your main challenge

will be how to embed them into your project. For soft

garments, get creative with snaps or hook and loop

fasteners so that the electronics can be removed for

washing. If your sewing machine has a buttonhole

function, adding buttonholes to a garment is an

easy way to make passthroughs for wires. For rigid

accessories like helmets and headsets, use hot glue or

strong adhesive tape to attach your circuit.

SEWN CIRCUITS

Sewn circuits, also known as e-textiles, are also a great

place to start. Sewn circuits use conductive thread

for electrical connections, no soldering necessary! To

build your circuit, you simply sew from one component

to the next. There are many types of sewable

components available, including microcontrollers,

sensors, LEDs, and more. Sewable components have

large, open holes for making electrical connections

with conductive thread, and some are even washable.

You may already have the hand sewing tools you

need for sewn circuits: large-eye needles, scissors,

and a thimble. You’ll also need conductive thread

BUILDING

YOUR CIRCUIT

and sewable electronic components for your circuit.

Conductive thread is thicker than regular thread,

and a dab of Fray Check or superglue will help keep

knots tied.

Because conductive thread is not insulated, it can

be difficult to avoid short circuits, and you will need to

insulate your sewn circuit when it’s complete. Cover

the thread lines with puff paint or strips of fusible

interfacing. This usually works well on the inside of a

soft project, but think about the outside too – a long

run of conductive thread can fold back on itself and

cause a short circuit. Because of the resistance factor

of conductive thread, insulated wire is a better choice

for long circuits.

Despite the challenges of building large projects

with sewn circuits, great complexity can be achieved

with clever engineering and imagination. Masters of

sewn circuits embrace the constraints of conductive

thread and turn circuits themselves into works of

art. However, if sewn circuits are your entry point

to electronics, it’s likely that the limits of conductive

thread will drive you to learn to solder. We love

that idea!

SOLDERED CIRCUITS

If you’re new to it, learning how to solder may seem

daunting, but it’s fun and easy once you learn the

basics. A quick lesson from a makerspace or an

experienced friend can get you started. Then it’s

a matter of practice, and investing in the tools: a

soldering iron, metal solder, wire strippers, and wire

for your project. Silicone-coated stranded wire is

great for wearables; it’s soft, flexible, and can be

W

Above

There are lots of

power options for

choose from

Choosing

a battery

for your

project is

a balance

between

size and

power