Printed Electronics Aids New Directions in Medical Diagnostics and Treatment

People with diabetes must frequently test their blood glucose levels to manage their condition, as often as three times a day. The disease affects about 371 million people worldwide, and consumer test strips from a number of manufacturers have made it quick and efficient to accurately obtain readings and help those afflicted live as normally as possible.

Printed electronics, also known as organic and flexible electronics, produced by screen printing, offset lithography, and inkjet printing, has been the technological facilitator of these test strips. It has produced devices that are uber-thin and can bend, which are rapidly being adopted for not only next-generation medical testing and treatment, but also for flexible consumer electronics, thin-film photovoltaics, and other applications.

PolyPhotonix’s Noctura400 Sleep Mask, which uses photonics and printed electronics to provide home treatment for a condition called diabetic retinopathy, one of the leading causes of blindness in the world.
(Source: Centre for Process Innovation)

Steven Bagshaw of the Centre for Process Innovation, a UK-based technology incubator, said the printing of electronics, on plastic, paper, glass, and metal, opens up electronic functionality and a host of design opportunities, as it means that electronics no longer have to be produced on rigid circuit boards.

‘The ability to develop flexible form factors increases the freedom for designers to embed technology and functionality into their products,” Bagshaw said, “creating the opportunity for new, innovative components that can be wireless, smarter, interactive, conformable, thinner, lightweight, rugged, and which blend more easily into the surrounding environment.”

[Learn more about flexible electronics for medical applications in a session called "The Next Generation of Sensors and Flexible Electronics" at Pacific Design & Manufacturing, Feb. 9-11, at the Anaheim Convention Center.]

In the case of blood glucose-measuring test strips -- like OneTouch, from Johnson & Johnson’s LifeScan division -- screen printing and thin-film deposition are the two main ways the strips are made, said Robert Marshall, director of strip platforms at LifeScan Scotland.

“The most commonly used methods involve either traditional screen printing of inks and/or pastes containing a specific formulation of conductive materials and active chemical ingredients or the use of thin sputtered films of metal, such as palladium or gold, which may then be laser ablated, or etched, to create a desired electrode pattern,” he said.

The strips work via electronic materials that are activated when a person puts on a drop of blood. The strip is plugged into a meter, which transfers an electrical current to the test strip that reacts with the electrode layer on the strip to read a person’s blood-glucose level, explained Harry Zevos, principal analyst at IDTechEx. “Depending on how high or how low [the current] is, you get a measurement for what your blood glucose is,” he said.

New Medical Applications

The market for these test strips is more than $6 billion and growing, Zevos said, by far the biggest application of printed electronics in the medical field. But new applications stemming from printed electronics are poised to emerge and help in the diagnosis and treatment of conditions and chronic diseases.

One of those areas is known as healthcare photonics, an umbrella term for the use of light to diagnose and treat medical conditions, the Centre for Process Innovation’s Bagshaw said.

Healthcare photonics includes a range of new phototherapies as well as bio-medical imaging and in vitro diagnostics, and offers “huge potential” for the global healthcare sector, he said. Applications range from care for wounds, the skin, and cancer, as well as niche uses in neurology and ophthalmology.

The area is so ripe that CPI is opening the new National Centre for Healthcare Photonics in 2018 to provide open-access facilities and expertise to help companies develop photonics-based technologies and bring them to commercialization. The facility will be designed for use by companies of all sizes, from major multinationals to SMBs, as well as universities, Bagshaw said.

Where printed electronics comes into play in healthcare photonics are flexible and printable lighting films that can be used for delivering phototherapies, as well as printed organic photodetectors for use in medical imaging, he said. “Photonics-based technologies can be integrated with other printed, lightweight, and flexible devices in point-of-care diagnostics and instrumentation.”

One example of a medical device that already uses printed electronics in the healthcare photonics space is the Noctura400 sleep mask from PolyPhotonix in the UK for the treatment of diabetic retinopathy, a common cause of blindness, Bagshaw said. The sleep mask is a home-based therapy device that offers non-invasive treatment for the condition, delivered at a fraction of the cost of current interventions, which include laser photocoagulation surgery and intraocular drug injection, Bagshaw said.