Thin film electronics may hold the key to human size health care

Health care’s integration with information technology remains inconsistent as of today. Supercomputers helped fuel the genomics revolution, which was a critical success for the health care space. On the other hand, the transition to electronic medical records has been a promise never fully realized. The rapid adoption of wearables, though, leaves little doubt that electronics is poised to make a large impact on health and medicine.
As Gigaom Research analyst Jody Ranck writes in his forthcoming report on health care and the internet of things, sensors and other electronics will drive tremendous innovation in medical devices, building off the current momentum in fitness and wellness devices. Much of this development is centered on making devices ever smaller, from ingestible sensors in the form of pills to nanowires and lab-on-a-chip technologies.
This focus on miniaturization is no surprise. Silicon electronics has relentlessly followed Moore’s Law for the last 40 years, exponentially decreasing the size of a transistor. But in health care, smaller is not always better. Human beings are large and many things we want to measure, like blood pressure or muscle movement, require larger-scale sensors.
This is where silicon — an element so critical to the development of computing that its name adorns Valleys, Alleys and other centers of IT innovation — starts to falter.
Silicon is plentiful on Earth, but in the purified crystalline form required for semiconductors it is only cheap because many chips can be packed into a single wafer, enabling smaller devices. If larger sensors are carved out of a wafer, the economics aren’t nearly as favorable. Since, as mentioned above, smaller doesn’t necessarily mean better in health care, the key to fully realizing the promise of information technology may be to move electronics beyond silicon.
John Kymissis, a professor of electrical engineering at Columbia University, thinks he has the answer. Prof. Kymissis, who runs Columbia’s Laboratory for Unconventional Electronics (CLUE) has been researching thin film semiconductors.
Like the name suggests, thin film semiconductors are created by depositing a thin layer of electronics onto other materials. So instead of starting with a perfect wafer of silicon and carving out tiny transistors, you can pick a material that has certain desirable properties — like plastic or glass — and add the electronics on top. And in fact most of us benefit from thin film semiconductors every day in the displays of our smartphones, tablets and HDTVs. But beyond the display market there are promising applications for future development.
I met Prof. Kymissis at NYC Media Lab’s inaugural Geek of the Month gathering where he discussed projects in this lab that are trying to advance the state of the art in thin film semiconductor systems. Many of these projects focus on health care applications because, as Prof. Kymissis puts it, “Engineering is about solving problems and health care folks have the biggest problems.”
One interesting solution CLUE is working on involves using a material called piezoelectric polymer as a substrate. Piezoelectric systems generate an electric charge in response to physical stress. This is the same the principle behind how cigarette lighters ignite (or push-start buttons on gas grills, to pick a slightly more healthy example). The researchers at CLUE have added transistors to a thin flexible polymer film that responds to different strains, creating a microphone array that captures information about sound waves in a new way. One application of this is to measure the pressure wave inside the ear as part of a system that will aid in the placement of cochlear implants.

 Image courtesy John Kymissis, CLUE

A transistor microphone array on piezoelectric polymer Image courtesy John Kymissis, CLUE

Another material CLUE is investigating is electrostrictive polymer. This works in the reverse way of piezoelectric polymer: With the connection of an electric charge, the material will contract and bend like a muscle. Potential applications in prostheses and robotics are further off but one of the major hurdles is the fact that it requires approximately 500 volts to make the polymer bend. The team at CLUE is using transistors on the polymer to act as switches that control the movement at a much more reasonable 30 volts or so. This would open the door to building this technology into devices or other uses.
Thin film semiconductors still need work in important areas to realize their full potential. The technology can’t yet support wireless power transfer so for all the magic in the devices they still require a wire, which limits many use cases. You also can’t yet put a radio on a thin film semiconductor, which leaves them outside the truly connected world of healthcare IoT.
But there is plenty of research going on at CLUE and other labs around the country on these very topics. So while silicon isn’t going away it’s likely that thin film will continue to open up new applications to increase the positive impact of electronics in healthcare.
Ken Andersen is vice president of operations for Gigaom Research.
Thumbnail image courtesy of MauMyHaT/Thinkstock