If we have learned one thing from breathy concept designs and cheesy sci-fi movies, it is that we all deserve flexible technologies – bio-electric tattoos, that measure our vitals and tablets we can roll up to shove in our pockets. So, the main thing is where are they, as promised earlier?
It turns out that making truly flexible devices is harder than futurists and movie makers imagined. We increasingly see flexible technologies demonstrated at huge events, but manufacturers tend to show off a single function-a rollable screen here, a stretchable circuit there. Real-life gadgets need to bundle those features together into a neat package, and that’s proving to be a sticking point.
But some of the primary barriers to flexible electronics namely the development of stretchable circuitry bendable batteries are right now being figured out in research labs around the world. And if those challenges are overcome, you could be in line for electronics that are harder to damage, more reactive to their environments and change the way you physically interact with them.
As the great bent iPhone 6 debacle of 2014 demonstrated, many of today’s devices are not imbued with flexibility. That is because electronics use a complex combination of components, most of which cannot currently be bent. Processors are still etched in silicon wafer, for instance, and you do not want to think about what might happen if you bent the lithium-ion battery, that is powering up your phone.
The few examples of flexible electronics that do exist do not have much to recommend them. Consider a few of the examples we have seen recently. Way back in 2012, Wexler released the first ever flexible e-reader and Sony followed up with Paper in 2014. E-readers are not intrinsically exciting, but Paper packed a bendable 13-inch e-ink screen, despite its $1100 price tag hinted at a future of bendable tablets. But after two years on, we are still waiting, because nobody seems to have figured out what to do with the chips, memory, batteries and so on. In both those devices, they were simply stuffed into an inflexible lump at the edge of the screen.
At a much larger scale, Samsung and LG has shown off a TV that can automatically morph from curved to flat with the push of a button. But the screen for both the companies’ TVs is 105 inches each on the diagonal and the depth of the curvature can be measured in single figures of inches. So, the effect is more akin to gently flexing a giant credit card, than actually enveloping your face in pixels.
These shortcomings can all be attributed to a lack of flexibility in some key components. Imagine stacking a series of playing cards on top of each other. Then think of them as different parts of a simple flexible electronic device such as wiring, a battery, a processor and so forth. Bend the stack a little from the middle and everything moves in unison. Bend it aggressively, and the ends of cards fan out from each other. Your electronic circuits no longer marry up neatly.
But say you want something that conforms to more complex shapes, like a tablet you can crumple like a piece of paper. Thinking back to the stack of cards, you can not really do it, at least not easily, and you might end up damaging something in the process. Instead, you need the component parts or at the very least what links them together if they can be made small to be stretchable, so that the different parts can bend with each other into more interesting shapes.
Enter elastic circuitry, which is finally coming of age. Typically, this circuitry entails some kind of stretchable polymer that is modified to conduct electricity, and it is evolved in leaps and bounds in the last decade. In 2008, these types of electronics could stretch by around 70% while maintaining their conductivity. Today, it is possible to create similar fibers that stretch to over 1000% of their original length. Applied to an elastic polymer base, you can create a stretchable printed circuit board much like the one announced by Panasonic last year.
Some components are a little more difficult to flex, but fortunately there is a general trend in electronics that can help. “The trajectory of the traditional semiconductor industry is all around miniaturisation, making things smaller and thinner,” John Rogers, a professor in engineering from the University of Illinois said. “Those trends have relevance and importance for flexible electronics.” That means that some parts like radio antennae and simple sensors are naturally starting to become so thin that they will be flexible enough without much extra research.
Another option is to share resources that happen to be nearby. There may be no need for a device to come packed with powerful hardware when a lightning fast smartphone is around. We have seen that with smartwatches to some extent, and there is no reason it could not be the case for most flexible devices either. All that is required is some kind of wireless data link to quickly beam information back and forth.
There is still one major fly in the ointment. “Power supplies are a barrier,” Rogers admitted. “You can make most components small enough, in lateral dimensions that you can engineer the soft mechanics you ultimately want.” But that is simply not the case with batteries, where the capacity of a cell is dictated by its volume. You make one thin enough to be flexible, and it barely holds any charge. That is of little use, especially given the rate at which most devices now chew through charge.
Wireless power is likely the best solution. “In that case all you really need to do is to create flexible antennae to receive the power,” Rogers said. There, devices seize the oscillating signals in the data streams of Wi-Fi and turn it into direct current. Currently it powers only small devices, but at this year’s CES, we saw Ossia’s wireless system charge an iPhone in mid-air, which will be a commercial reality by the end of 2016.
According to Rogers, we are approaching a point where ‘incremental engineering can be brought to bear.’ It is expected that flexible electronics will gradually improve over the coming years. Components will become more flexible, circuits will demand less power, and materials will make flexible devices more pleasant to interact with. “There are opportunities for research,” Roger said, “but I hope and believe we are placed for very rapid growth.”
There are plenty more potential applications where those came from. But, these kinds of technologies are revolutionary, not evolutionary. They are just a step change in the way we use electronics. The reason we are not seeing a bendable tablet yet may be almost as much to do with manufacturers taking small steps, in order to avoid overwhelming us, as it is with the readiness of the hardware itself.
Ultimately, truly flexible technology is an inevitable future from consumer electronics. We just need to be patient and more creative in doing anything. It would be great if I could roll my phone up and put it in my pocket in the future. Well, let us hope the success of flexible electronics, which is really going to change the lives of all tech enthusiasts and the general public in just direct one go!