Amazing Devices Enabled by Flexible Hybrid Electronics
The advice that young Dustin Hoffman received was right. The future really is in plastics.
Of course, Hoffman’s character in the 1967 classic film “The Graduate” was being advised on a much more general-purpose form and application of plastics, but it turns out the statement is equally relevant today in the tech industry.
Some of the most fascinating work in the development of new tech-based products is happening on “plastic-like,” clear, flexible materials. In fact, at an Innovation Day put on by NextFlex—a consortium of government, academic, and private companies working to advance and standardize developments in flexible electronics manufacturing—I got a chance to see numerous efforts to bring flexible hybrid electronics (FHE) into the mainstream.
Most of the developments on display were related to flexible replacements for the printed circuit boards that sit at the heart of today’s tech devices. While we don’t always think about it, the rigid form today’s circuit boards take have a dramatic impact on the shape, design, and form factor of the devices they power. With the advent of pliable boards, the possibilities for completely new types of applications and devices become enticingly real across a wide range of industries. In fact, the early experiments with flexible electronics stretch from consumer devices to medical components to commercial systems and military applications.
At the event, GE showed off wireless wearable EKGs that dramatically ease the often-challenging process of connecting multiple wired leads to the patches placed on a patient’s body for traditional EKGs. Contract manufacturer Flex and chemical giant DuPont presented printed electronics designed for clothing that enable things like fabric with built-in warmers. They also showed off athletic clothing and racing suits with integrated biometric sensors for more advanced wearable computing and health-monitoring applications. Lockheed Martin showed sensors that attach to the curved wings of unmanned military drones. Universities like Stanford, Purdue, and Georgia Tech also displayed their research work in areas such as smart bandages, and self-powered wearable electronics. There was even a group of high-school students talking about a Shark Tank-style event they competed in where they had to create potential applications for FHE.
Long-time tech industry observers might argue that this is nothing new. After all, weren’t people talking about “printing” electronics onto these types of materials just a few years back? The expectation was that you’d be able to use sophisticated inkjet print-heads and specialized inks to crank out roll-upon-roll of complicated circuits in a simple, fast, cost-effective way.
Truth is, the industry tried to make a go of it, but a number of technical and financial realities quickly sidelined those efforts—likely forever. As former tech analyst and current NextFlex Director of Commercialization, Paul Semenza, put it, the cost of fabricating a single transistor is nearly zero with the current, highly efficient silicon manufacturing processes, so any effort to improve on that would be futile.
Despite these initial setbacks, all was not lost though. As with many big picture ideas, some concepts embedded within the overall printed electronics idea did prove to be useful. Specifically, the ability to print the lines, traces, and other interconnect elements typically found on circuit boards—arguably the simplest part of the original idea—turned out to be a good, practical application of the concept and original technology. Conductive inks printed onto various plastic films are perfectly suited to that part of a circuit board.
The integrated circuits (ICs) that power these boards couldn’t effectively be printed, however, because of the cost issues mentioned earlier. So, did it take a sophisticated new breakthrough to overcome the IC challenge? Turns out, the solution to the issue is surprisingly straightforward—essentially, removing the vast majority of the packaging around the chip itself.
The tiny silicon components inside most chips can be rendered thin and fairly pliable—it’s been the harder, thicker packaging around the chips that has prevented them from being used to create flexible electronics. By taking those packaging elements away and applying some clever engineering to protect and attach the resulting “raw” silicon components onto the plastic substrate used as the base for the electronics, you can build completely flexible circuit boards. These boards combine elements of both flexible materials and traditional semiconductors—hence, flexible hybrid electronics, or FHE.
One challenge, of course, is that the more complex the IC—such as an Intel CPU—the less flexible it is, and the more challenging it is to use on a flexible circuit board. While it’s easy to assume that this is because of the size of the chip, it’s actually due to the complexity of interconnections required, and not its physical size. That’s why early efforts for FHE are focused on simpler chips, such as those used on the popular Arduino board. Arduinos are used by some device manufacturers and electronics hobbyists/makers around the world for an enormous range of different products and projects.
The notion of flexibility and the potential use of plastics isn’t limited to the circuit boards found inside tech products either. Manufacturers of display components, in particular, have been exploring and experimenting with plastic materials and flexible displays for well over a decade. While they aren’t technically a type of FHE, LCD and OLED panels do incorporate some basic circuits on them to control what is shown on the display. Already, companies like LG and Samsung are using plastic substrates, or backplanes, for a number of different commercial products, including the curved OLED screens on Samsung’s Galaxy phones, the iPhone X, smart watches, and other products. In addition to flexibility, one of the key benefits of using plastic substrates in a display is the reduced potential for breakage that commonly occurs with glass-based displays.
The next expected development in displays moves beyond simple flexing and into folding. Several companies, in fact, have already shown prototypes of devices like smartphones that you can fold in half to reduce a large-screen device into something that will fit in your pocket. The challenge for these kinds of displays—as it is for the flexible circuit boards—is building them reliably and cost-effectively in large quantities. There’s an enormous difference between being able to build a handful of prototypes and cranking out millions of foldable displays and circuit boards.
Thankfully, key advances in material sciences, manufacturing equipment, manufacturing processes, and more are starting to come together in a meaningful way, enabling the start of the flexible hybrid electronics era. While products built with these key component technologies won’t be showing up overnight, their practical applications are clearly coming into sight. Once they do, the possibilities for what tech devices can do, how they work, and what form they take are nearly limitless. In fact, you can even start to imagine a world populated by more organic types of computing devices.
Plastics, it seems, are indeed the future….