The realms of wearable and flexible electronic devices are two fields that are experiencing significant expansion and growth in various industries, with certain applications embracing devices that can be both wearable and flexible. In many cases, wearable electronics–especially new devices–will be flexible to conform to the user. Whatever the purpose three of these devices in the case of devices that can be both wearable and flexible become possible in their current configuration thanks to the advancements in nanotechnology throughout the years. If not for advances in manufacturing techniques that are efficient and processes, many of these wearable and flexible devices wouldn’t be possible since there would be no materials that could perform the essential tasks.
What Nanotechnology is at the heart of These Advancements
There are a variety of requirements materials must meet for use in electronic devices that are wearable and flexible. One of the most obvious one is that it must be extremely thin and flexible. If they’re not very thin they won’t bend effectively and be vulnerable of stress cracks. However, certain materials are not able to bend and aren’t effective as well. Although they may be useful in some wearable devices most modern electronic devices need to fit the needs of the wearer in one way or other way. All in all, electronic devices, that are highly flexible need to be durable and durable to fracture when subjected to bending or the torsional stress.
There are two other properties that are highly beneficial but are application-dependent. The two characteristics in question include a high electrical conductivity and consequently, a high mobility of charge carriers–as well as a high optical transparency. For a variety of monitoring and sensor applications it is essential to have a high electrical conductivity. This is essential because when materials are subjected to changes from to a stimuli in the local environment the change is detected through the changes in conductivity of the sensor material(s) inside the device. This is the nanomaterial used in flexible/wearable sensors. On the other hand transparent optical properties are more appropriate in other situations where light must be able to flow through the device, or some of the devices. Flexible screens are an example of application.
There aren’t many materials that exhibit all these characteristics. The emergence and development of nanotechnology has produced several materials with many, if certainly not all of these properties. There is no other field that has been defined as a specific area of materials ranging from organic molecules to crystal-state inorganic complexes, as well as micro manufacturing — can produce materials that have characteristics that are perfectly aligned with the needs of these devices. This is why nanotechnology is essential in the commercialization the devices. However, there is an increasing trend of creating flexible electronic devices using elastic organic molecules specifically polymeric materials, however they’re currently lagging behind nanomaterials in terms effectiveness. However, it is an emerging area gradually expanding. This is due in part to the majority of organic electronics being print-ready and flexible, however the field that is flexible electronic devices an issue to come up with a topic for another day.
Another reason is that nanotechnology is at the leading edge of developing these electronic systems as many nanomaterials can be tunable, their properties can be altered and the manufacturing process can be adjustable. This means that their localized structures of nanomaterials is able to be altered and manipulated throughout the process of manufacturing process, or they could be functionalized and doped following their formation. All of these elements alter the characteristics of the nanomaterial so that they satisfy the requirements of the particular application. This flexibility has made nanomaterials a flexible element for the construction of many modular and wearable electronic systems.
Nanomaterials have not been without its difficulties however. Carbon nanotubes (CNTs) were among the first nanomaterials studied, but there were issues getting them dispersed and aligned CNTs. Since they were first introduced, CNTs issues have been resolved however the field has moved to other nanomaterials, specifically, diverse 2D materials. While 2D hexagonal hexagonal boron nitride and transition metal Dichalcogenides (TMDCs) materials are used in the field of flexible electronic devices however, graphene has demonstrated the greatest potential and has been extensively utilized. There are a myriad of reasons for graphene, however the most straightforward reason is the graphene is able to fulfill every property requirement in wearable and flexible electronic devices:
- It is the most well-known for its conductivity in electrical power and charge carrier mobility of any substance.
- It’s a highly elastic material in single layer, but it becomes less flexible as you increase the layers.
- This material has an optical transparency that is 98.7 percentage, meaning it is able to make high-quality, transparent devices.
- It is extremely strong in its tension strength.
- It is extremely durable and has durability to high temperatures as well as pressure and chemical environments.
Other materials worth looking for in this area include quantum dots and nanowires since they have the potential to be integrated into wearable, flexible electronics , and have unique properties.
The Key Areas of Application
There are two major areas in which flexible electronics have come into commercial application or are being developed. Flexible solar cells and touch screens that are flexible. For flexible screens available in the market the most popular is Organic Light-Emitting Diodes (OLEDs) that are leading the method (a thin layer composed of organic molecules layered that is layered on top of another) However, companies are beginning to look for the potential of using quantum dots in OLED devices. In addition, several flexible screens made of graphene are available now, where polymer and graphene layers are placed on top of one and then stacked on top of each. There is a rumor that the first commercially accessible fully foldable smartphones as well as laptops that utilize graphene might appear as early at the end of next year.
When it comes to solar cells made of nanomaterials, their efficiency is increasing. While their efficiency isn’t quite like similar solar cell types, they are modified by with nanomaterials. They can therefore be shaped to fit the geometrical shape of buildings that allows them to absorb more photons from the sun. Therefore, their energy conversion efficiency may not be as efficient however, they do have the capacity to collect more photons which can be converted to electricity. Another area of growth is the development of nanomaterials into the form of ink, where they could be used to create solar cells that can be printed.
One of the most important areas where the concepts of flexible and wearable electronic devices is in medical sensors that are used for medical diagnostics, health monitoring as well as exercise tracking. Flexible electronics employ nanomaterials to ensure they conform with the contours of skin and function as sensors. In certain instances they may be placed on the body of the patient and monitored remotely using the Internet of Things (IoT).
Every application makes use of the distinct characteristics of the nanomaterial to meet an individual use, to create a customized method. As manufacturing techniques improve further, we will see more wearable and flexible electronic devices hitting the market.
In the end, the advancements in the fabrication process and the tinkering of properties of nanomaterials have helped the field of wearable and flexible electronics to expand. In the present there are numerous applications being developed in the world of academia which are under development. With the speed of technological advancement in nanomaterials this shouldn’t be too long before these advances become more flexible and wearable electronic devices.