Hardware needs to squeeze itself through a serious bottleneck if wearable technology is going to catch on.
The trouble is that, until now, circuits and semiconductors have all been made of out metal, and metal is neither comfortable to wear nor practical as a fashion textile. It's stiff, inflexible and won't last very long if you put it through the wash.
Read this: The best smart clothing for 2015
So, if our smartwatches and smart garments, packed with activity sensors and biometric trackers, are going to stand a chance of delivering on their promise, we're going to need a whole new generation of e-textiles and future fabrics to make them. Materials that look a little like these...
We're used to thinking about battery problems in terms how how long they last but there's a second struggle that wearables have with these Li-ion cells - their relationship with size. If you want lots of capacity, you need a physically larger battery. That might be OK in a phone but in a smartwatch, a biometric sports shirt; well, that's difficult. So, do designers create something uncomfortable and chunky or a yet another possession that needs chaining to the mains?
For a long time, the holier grail has been items that can harvest ambient energy from their environments such as heat, friction or even electro-magnetics but the practical reality is still a long way off. So, instead, companies like South Korean firm Jenax are sticking with tradition but changing its shape altogether.
Read this: The death of charging
Looking more akin to a crisp packet, the Jenax J. Flex can be bent, twisted, scrunched, folded and crumpled into whatever space is available. It can hold up to six times the charge of a traditional smartwatch battery and that's about the same as a normal smartphone battery.
The J. Flex is currently going through testing and is doubtless not economical enough work its way into your next wearable purchase, but paper thin batteries are very real and very ready to make the wearable world a far better place.
Flexible fabric circuits
It's not just batteries that need to change shape in the connected self revolution. We're getting away with sticking smartphone chips in smartwatches at the moment but the wrist is not the ultimate destination of all things wearable. Not only is it not the most accurate place to measure biometrics but not everyone wants to put on a band or a timepiece there in the first place. Instead, the new focus is going to be about getting clever with how we build electronics and how we can get devices to work with maximal ease and minimum profile.
Ralph Lauren's Polo Tech Shirt is probably the first commercial step into this world. The garment itself is woven using bio-sensing silver fibres which can take readings of heart rate, muscle activity and other stats direct to the brains of the outfit at the side of the clothing. At first silver might sound impractical for mass market but Ralph Lauren isn't the only company exploring its potential. Jenax again also has a stainless steel cloth available which is not only conductive but also tough and provides thermal insulation.
Read more: 5 innovations that will change wearable tech
Currently, neither of these solutions get round the issue of having hard, non-flexible chips somewhere in the garments to do all the computational work but there's plenty of research into changing all that. Xiao Ming Tao and her team at the Institute of Textiles and Clothing in Hong Kong have invented fabric-based circuit boards that are entirely indistinguishable from normal attire. Woven with the copper wiring directly into the yarn. It's durable, stretchable and you can run it through the wash and it'll still work just fine; perfect for turning smart clothing into practical items we can really live with.
Getting shirts woven with metals is not the cheapest or most sustainable idea in the world. That's why MC10, a Cambridge, Massachusetts-based electronics company, has managed to reduce your wearable down to the invisible level in the creation of the Biostamp sticker. This sticks to the skin's surface and is powered by thin film battery tech.
How is it so tiny? Silicon transfers are thinned to a fraction of the width of a human hair and then combined with stretchable interconnects and elastic polymers. The results are chips that you can adhere faithfully to just about any part of your body and even internally direct to organs like the heart and the brain if you choose. They could detect cardiac and muscle activity in athletes, monitor health conditions or simply become the casual wearable alternatives for those that don't want to wear anything much at all.
Somewhere between living and non-living lies the idea of protocells. Protocells were the precursors to life in the days of the primordial soup of Earth 4.5 billion years ago. These were highly simplified chemical cells with some of the characteristics with which we associate being alive. They can respond to their environment; they can move, divide and fuse; they can change and adapt even if they do so without any intelligence or without the means to reproduce.
We know this because they're easy enough to recreate from all sorts of different materials in the lab as the University of Denmark's Dr Martin Hanczyc, and others, have done in order both to study the path between non-organic and organic but also to gain a better vocabulary of life in case we ever encounter something in the far reaches of space that we don't quite recognise.
Interesting stuff, but what does all of this have to do with wearable tech? Well, having clothing that's very literally alive would seem a little cruel but wearables that were made of something that could respond to your needs, without you having to tell them, would be incredibly useful, and that's why items made of protocells could be the perfect medium.
One idea by designer Shamees Aden was to create a pair of shoes for barefoot running which she called the Amoeba Trainer. Made of protocells, they would be able to respond to pressure, light and heat and so inflate and deflate themselves and provide support depending upon how firm the running surface is. When you take them off at the end of the day, you stick them in your jar of protocell energy liquid and they're ready to go again.
While it might not be convenient to have every item of clothing made from protocells, we might be talking about watch straps and gloves that mould themselves to fit you better or even shirts that get thinner as the ambient temperature increases. Ultimately, there's virtually limitless behaviours that can be programmed in depending upon what chemicals these protocells are made from.
This is all at a highly conceptual level at the moment so don't expect to find it in the shops any time soon. Just be patient.
Miracle materials - Graphene & Silicene
Start making structures from material sheets that are just one atom thick and the mind begins to boggle at their possible applications. That's what we're capable of building with the much-written about graphene miracle material. It's amazing strongly, astonishingly light, wonderfully flexible and a superb electrical conductor to boot.
The only trouble is that it's currently one of the most expensive materials to produce on Earth. Fortunately, the EU has chucked €1bn into figuring out how best to use the stuff and, with a list that spans everything from the biomedical to energy harvesting, there's more wearable tech crossovers than you can shake a smartwatch at. Everyone from Samsung to Plastic Logic is interested in the potential for, amongst other things, flexible graphene displays.
Almost identical to graphene but with a one-atom thick silicon hexagonal honeycomb structure, instead of carbon, is silicene. Until recently it was only a theoretical material but researchers at the University of Texas have managed to fabricate some and show that it could be made into transistors which could ultimately form the thinnest electronic chips known to man. All it needs is a nanometer thick layer of metal on top to keep it all together; low-energy, high-speed computing in the most convenient form possible. It's on the way but it might be your grandkids that get to enjoy it.
Biopolymers are long chain materials produced by living organisms. There are a lot of different kinds and they're not all good for making wearables from. For instance, DNA is a biopolymer but it's one that might be best kept inside your cells.
The most abundant biopolymer around, though, is cellulose which is found in the cell walls of all plant cells. While it's of less use to us in that form, it's possible to convince yeast and fungus to create sheets of bacterial cellulose that come out very much like a vegetarian version of leather.
It's easily worked into garments - smart or otherwise - it's entirely compostable when it's time to throw it away and it's completely carbon neutral.
Biocreative design agency, Biocouture, has done just that with founder Suzanne Lee's vision that microbes will be our living factories of the future with clothing that will even repair and adjust itself as needed.
While all that might seem a little bonkers at present, biopolymers are in use today as effective wearable solutions to incredibly worthwhile issues. The Foxleaf bra is an item in its latter stages of development, designed by Sarah da Costa with those at risk from breast cancer in mind. It houses a biopolymer at the cup where the best practice drug, tamoxifen, can absorb directly into the skin instead of causing aggressive side effects when taken orally.
Take a look at our interview with da Costa on World Cancer Day for more details, and the next time you put something on, don't forget to take a much closer look at what materials it's made from.