Bench Talk

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Electronic circuitry, whether it’s in the form of a simple circuit or a more advanced printed circuit board (PCB), has been crucial for realizing many of today’s technologies. What started as a way of transporting electrons to power simple devices has evolved into a high-tech affair where circuit boards are getting smaller and more efficient to meet the consumer demands of higher-powered and smaller electronic devices.

The next-generation of PCBs and circuitry requires new advances to meet demands, and the use of nanotechnology over the past few years has helped produce the current generation of circuitry modules. It will continue to do so in the years to come. Here, we’ll look at nanotechnology’s role in advancing circuitry design and development.

Although many of the existing materials are considered a staple in circuit board design, the top-down manufacturing approach has size limitations. This is where nanotechnology has come in. For one, many advanced top-down nanofabrication techniques enable the overall size and the patterns on the surface of PCBs to be smaller.

However, even top-down nanofabrication methods have size limitations, so nanotechnology has also helped create circuit boards from the ground up, such as building circuit boards atom by atom to create much smaller circuit boards than are possible by top-down approaches. Building atomic structures and devices in this way are known as bottom-up approaches and will become a useful tool for ushering smaller and more advanced PCBs and more complex circuitry requirements.

It’s not just the size of the PCB that has been improved because of nanotechnology. Components integrated into the PCB have been revolutionized in both size and performance. One of the best examples: transistors. Many nanomaterial-inspired transistors are used on circuit boards because of their enhanced performance and smaller-than-average size―meaning more transistors can be integrated into a defined area, improving the speed, power, and capabilities of the PCB.

In some cases, it’s not feasible to reinvent the circuitry if it is more than adequate for the intended role because many devices do not need enhanced performance capabilities. However, some of what might be considered lower-tech applications are often in environments where they can become damaged (such as environmental, remote, and chemical process monitoring applications). In these situations, nanomaterials can also help in the form of electronic coatings.

Although electronic coatings have been around for many years, those that utilize nanomaterials as the active material tend to be thinner on the surface of the PCB (so it’s not as thick). They are also more conformal to the complex geometry of PCBs, are uniform to the nano-level, offer better performance, and introduce many different effects to the PCB. In some instances, some nanocoatings are used to protect the PCB against various environmental factors―such as impact, abrasion, and water/moisture. In contrast, others are used to dissipate any localized heat that can arise within a device (such as heat spots). Others are used to enhance the conductivity of the PCB and any components that are attached to it (conductive coatings). So, in many ways, nanomaterials can be used to enhance PCB properties without directly integrating them into the PCB itself.

As well as creating and improving the average circuit via advanced fabrication and coating methods, nanomaterials have been used to create circuitry in areas that are not possible with traditional materials, namely flexible circuitry for wearable and flexible electronic devices. Most materials for traditional circuits are inorganic. But for these circuitry areas, most nanomaterials used are organic, such as conductive polymers and graphene. One odd inorganic example is also in use, with silver nanowires being the main one.

Such approaches wouldn’t be possible without advanced nanomaterial manufacturing and design. Flexible circuitry is being utilized in several applications areas, including flexible phones, health and fitness monitoring devices, radio frequency (RF) identity tags, and in a wide range of sensors. Nanomaterials have also been used to create specialist conductive inks that can be printed. These developments have elevated the area of PCBs to new heights, as many can be created using inkjet printers.

Aside from being used in the circuits of standalone wearable electronics, nanomaterials can also be used as the circuitry of electronic textiles (e-textiles). In these scenarios, nanomaterials are integrated into the textiles to act as a conductive conduit to power the devices embedded within the textile―either in a pure form, nanomaterial composite fiber, or as a conductive coating depending on the intended application, the type of nanomaterial, and the devices being powered within the e-textile.

Circuitry and printed circuit boards (PCBs) are always advancing to improve their performance and size to meet modern-day society’s demands. Nanotechnology offers a way of improving existing circuitry through advanced fabrication methods and nanocoating approaches. Nanotechnology also creates circuitry solutions that might not otherwise be possible―such as flexible circuitry in wearable and flexible electronics. Overall, the advances in nanotechnology and nanoscale fabrication methods have helped to get circuits to today’s levels, and nanotechnology will likely play an increasing role in future circuit designs.