Four medical device engineering challenges that electrically conductive plastics can solve

Conductive compounds provide the mechanical properties device designers expect, plus conductivity, sensing and static control.

By Matt James, Premix

As medical devices and medical infrastructure become smarter and smaller, design simplicity, monitoring improvements, shielding enhancements, and feature density all generate challenges for engineers. The right material can make or break a medical device development project.

The good news is that electrically conductive plastics can address some of those challenges. Unlike standard plastics, conductive compounds provide the mechanical properties designers expect, along with conductivity, sensing, and static control, all in a single part.

Designers can now move away from the sole objective of swapping metal for plastic. They can rethink device architecture and incorporate useful electrical functions much earlier in the design process.

For teams considering the use of conductive plastics, the first step is defining what the material can do. Electrical parameters are specified alongside mechanical properties, processing method, regulatory requirements, cleanliness requirements, and long-term consistency.

Here are four device design challenges where electrically conductive plastics may be the solution:

1. Incorporating conductive plastics in laboratories to reduce complexity

Reduction of complexity by adding technology to improve outcomes is a constant challenge for device development teams. The approach that has been the gold standard is capacitive sensing. Capacitive sensing provides accurate measurements with contact, and conductive plastics simplify packaging.

For example, automated liquid-handling systems can benefit from capacitive liquid-level sensing to improve accuracy and repeatability.  A pipette made with electrically conductive plastics can be used in an automated system to detect when the tip contacts the liquid, eliminating the need to fully submerge the tip. This can improve performance by reducing time and error rates.

Static control is an issue in medical and healthcare laboratory environments. Staff electrostatic discharge, disruption of sensitive lab equipment, and ignition risks with flammable agents are all real concerns. When conductive and static-dissipative plastics are incorporated into the component, ESD protection is handled at the component level rather than as an add-on. These materials still enable sophisticated forms and high-volume manufacturing through injection molding.

2. Boosting patient monitoring

Wearable healthcare devices, ECG, EEG, EMG, heart rate monitoring, sensing systems, and more are all moving toward lighter, smaller form factors. This trend is prompting device designers to incorporate dissipative plastic compounds instead of heavier, more traditional metal-based solutions.

For instance, rigid electrode structures, grounding features, and disposable sensor housings can be designed with conductive polypropylene. For products like heart rate belts, motion tracking patches and smart textiles, conductive thermoplastic polyurethane can be used in combination with other components in the assembly without the need to redesign the device architecture around metal usage. And the development of MRI- and X-ray-compatible disposable ECG electrodes made of conductive polypropylene opens new design approaches for patient monitoring devices.

3. Building safer healthcare environments

Healthcare environments house sensitive imaging systems, monitors, lab instruments, electronic health records, and diagnostic measurement systems. Without ESD control in place, electronics are damaged, patients can be shocked, and sterile surfaces contaminated.

More teams are beginning to approach electrostatic issues in hospitals as a design requirement from the outset, rather than something to address after the fact. The new Assi Hospital in Finland is an example of where designers considered the electrostatic matters early and addressed requirements to meet IEC 61340-6-1 for control of static in healthcare environments.

With conductive and dissipative plastics, components such as hospital beds, carts, diagnostic trolleys, furniture, wheels, and static-safe gas tubing can be designed to reduce the risk of damage.

4. Multifunctional medical plastics on the horizon

Conductive plastics can combine the electrical functionality of a device with the beneficial properties of polymer processing. They’re light weight, offer shape freedom, can incorporate complex shapes, and are compatibile with injection molding or extrusion.

In smart medical consumables, conductive plastics can replace metal electrodes or contacts to support more integrated part design. These include (but are not limited to) diagnostic consumables such as disposable electrodes and electrochemical sensors.

Designers are no longer asking whether plastic can replace a particular metal component, and asking whether the material itself can do more to fulfill what the device needs to do.

This shift is more relevant as healthcare moves towards automation, remote monitoring, miniaturized diagnostics, connected devices, and smart disposable components.

Matt James is sales director, North America at Premix, with decades of experience in the plastics industry spanning engineering, application development, project management and technical sales. His background includes work with polymer materials, plastics processing, and customer application development, helping manufacturers solve technical challenges with electrically conductive and static-dissipative plastic solutions.

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The opinions expressed in this article are the author’s only and do not necessarily reflect those of Medical Design & Outsourcing or its employees.