Next-gen medical polymers for smart, sustainable healthcare devices

Smart and sustainable – those are two words that can be used to describe the direction in which many industries, including medical manufacturing, are trending. Smart devices – including remote monitoring technology and other medtech with embedded electronics – are a fast-growing segment of the medical manufacturing industry, while manufacturers and medical professionals are increasingly aware of the need to lower their carbon footprint as the industry expands.

Materials play a large role in meeting these needs. Polycarbonate supplier Covestro is embracing the challenge of creating advanced solutions meeting the increasingly complex requirements of medical devices while maintaining strict sustainability goals. The company’s Engineering Plastics unit offers a range of polycarbonate and polycarbonate blends, including high heat options. Some of those materials are turned into films, but the Specialty Films side of the business also develops thermoplastic polyurethanes (TPU) as well as multilayer products.

Remote monitoring with versatile films

These two business units frequently work together, integrating rigid polycarbonates and flexible films into applications such as smart medical devices and wearables. Ken Schwartz, head of growth and innovation – Specialty Films, cites a growing interest in home monitoring devices as a driving factor for the development of new materials. He points to how Covestro’s TPU films can be used in wearable applications such as continuous glucose monitoring (CGM) patches.

“TPU has great adhesive anchorage along with flexibility and, most important, breathability, along with water resistance and chemical resistance,” he says. “The breathability function is what allows for greater wear time. You’re not getting moisture trapped under there – it enables the moisture to diffuse out, keeping the adhesive stuck onto the device and the skin, allowing for greater wear time along with comfort.”

Covestro’s Platilon TPU portfolio is specifically formulated to integrate flexible printed electronics into comfortable, discreet wearable devices. For another example, the company was involved in the development of a pulse oximeter with electronic circuits printed directly on a thin Platilon TPU film, offering a stretchable, lightweight alternative to traditional rigid plastics. The film can also be made in different colors, textures, and skin tones.

“It’s new for the market to see applications where TPU is used as a substrate for both mounting components and printing conductive elements,” Schwartz says.

Adaptable AI

On the Engineering Plastics side, Covestro’s Makrolon 2458 polycarbonate was used in the manufacture of InfoBionic.Ai’s MoMe ARC system, which was recently released in its third generation. The U.S. Food and Drug Administration (FDA)-cleared remote cardiac monitoring device detects arrhythmias in the wearer and transmits data to physicians via an app. The artificial intelligence (AI)-enabled system can be configured to suit individual patients’ acuity levels.

“If you’re in the hospital and you need to have a significant diagnostic version of a heart monitor, it can proceed that way, but if you’re going to be released from the hospital and go home but also need to continue further monitoring, the device can be adjusted so it’s a little bit less sensitive and more friendly to a home environment,” explains Emily Shaffer, healthcare market manager, Americas – Engineering Plastics. “There are two different ways you can use the device. It has a modular sensor pod that clips into a single disposable patch that adheres to your skin, or in the other version it connects to a six-lead, more traditional-looking cardiac monitor system.”

Makrolon 2458 was used in the previous generation of the device as well, allowing InfoBionic.Ai to maintain brand consistency in the new release. The biocompatible material offers durability and impact resistance along with aesthetic qualities such as translucency, necessary for status lights to shine through.

Keeping up with post-COVID chemical, sterilization shifts

Covestro has honed its polycarbonate materials for more than 50 years as a supplier to the healthcare industry. The rigid plastics are used in everything from dialyzers and blood oxygenators to minimally invasive surgical tools. They can be molded into thin walls while remaining tough, allowing for smaller, better-fitting, yet durable devices. They can also offer increased chemical resistance.

“What we’ve noticed since the post-pandemic shift is disinfectants and cleaners continually get more and more aggressive in hospital and home settings,” Shaffer says. “We see a good demand for materials that have higher chemical resistance. We’re also seeing some innovation happening on new sterilization methods – moving away from more of the traditional gamma, electron beam (E-beam), and ethylene oxide (EtO) sterilization.”

New sterilization techniques mean materials used in medical devices must be able to withstand them, offering new challenges for material developers. Shaffer also points out chemical resistance isn’t just about harsh disinfectants – wearables in particular must be unaffected by lotions, hand sanitizers, and other everyday chemicals contacting users’ skin.

Mass customization, drug delivery, and beyond

As wearables become more common, manufacturers are tailoring them toward the patient as a consumer, making them more aesthetically pleasing with design and color modifications. Comfort and appearance contribute to patient compliance, so Covestro relies on its global color and design centers to develop colors, finishes, and textures to appeal to the wearer.

Films are particularly suited to mass customization, according to Schwartz, and another area of high demand for Covestro is wound care. Treating a wound or burn has gone far beyond applying an off-the-shelf bandage; advanced polyurethane (PU) and TPU materials can be tweaked to offer optimum healing benefits for various injury types. Covestro has developed multilayer films that can be tailored to characteristics such as breathability and pressure while maintaining a strong viral barrier. In larger, more complex wounds, these characteristics can also be monitored by printed electronics incorporated into TPU films.

Connectivity is one challenge Covestro plans to focus more on. The company has a TPU product portfolio geared toward printed flexible electronics and is now looking at taking those materials to the next level based on unmet needs in the market, gathered via a recent customer survey. Covestro recently developed a functional demonstrator to show the potential of printed electronics: a shoe insole including two layers of TPU film, a sensor with force-sensitive ink, and printed conductive circuits. It measures the differences in load on various areas of the foot, offering potential for orthopedic or athletic applications, and is thin enough that the wearer won’t feel it. The next step, so to speak, is to evolve the design into something that can hold up for a few hundred miles.

Covestro also has an eye on increasing development of products geared toward diagnostics and drug delivery. As demand grows for GLP-1 drugs, which are shifting from diabetes management to weight loss solutions, it leads to increased demand for self-injection devices. A few years ago, Covestro launched a portfolio of low-friction polycarbonates, solving design requirements such as ensuring the button of an autoinjector can be pushed more easily and consistently.

“We constantly innovate to improve existing devices, but also consider ‘what new devices might be needed as successful drugs continue to grow?’” Shaffer says. “And then do we need to innovate additional products to accommodate them?”

As Covestro continues to develop new ideas, sustainability is always top of mind. The company recently expanded its low carbon footprint medical product portfolio with the addition of several polycarbonates made from recycled and/or bio-waste materials, often manufactured using renewable energy. Both the film and engineering plastic business units offer sustainable options and are working to develop more as demand increases.

“We see OEMs looking to put their stamp on a low carbon footprint even with additional expense,” Schwartz says. “It’s hard to use non fossil fuel-based precursors and the materials just don’t cost the same, so it really requires a commitment from the brand owner to make that investment. And we’ve seen it. We’re excited about it but we’re not quite there yet.”

He mentions efforts in the works of getting International Sustainability and Carbon Certification (ISCC) for Covestro’s Specialty Films value chain, in addition to the multiple certifications the company already has – a demonstration that business success and environmental responsibility are far from mutually exclusive.

Covestro
https://www.covestro.com

InfoBionic.Ai
https://infobionic.ai

About the author: Clare Scott is associate editor of GIE Media’s Manufacturing Group. She can be reached at CScott@gie.net.