A key to flexible electronics: Samsung and Stanford Ease Manufacturing
Flexible electronics have been a hot research area for quite some time now, and the more time passes, the more it seems to develop.
Advocates of flexible electronics often envision future technologies used in devices such as foldable smartphones, smart textiles, wearable electronics, and implantable sensors; all are heavily invested in universities and industry.
An example of a hybrid system with printed and flexible integrated circuits. Image of American semiconductor
Yet, like all technology in its infancy, there are many hurdles to overcome, especially in this hazy area between academic research and bringing to market. Fortunately, with the momentum in the field of flexible electronics, developments seem to be happening at lightning speeds. This month alone has seen many advancements in the field in academia and industry.
This article will discuss two academic developments to see where this industry might be heading and what challenges lie ahead. The first university company with flexible electronics came from Stanford.
Stanford’s flexible manufacturing technique
Recently, Stanford tried to innovate the process of create flexible electronics.
Most efforts towards flexible electronics have often involved the use of atomically thin 2D electronics, materials with a single atomic thickness, making them flexible and bendable while maintaining excellent mechanical and electrical properties. However, forming these ultra-thin devices generally requires an extremely hot manufacturing process, so hot that flexible plastic substrates in electronics would melt and decompose during the production process.
The transfer process (stages af) of the new flexible manufacturing technique. Image of Daus et al
In a new paper at Stanford University, researchers are proposing a new method of manufacturing these flexible 2D electronic components.
The technique involves taking a solid, non-flexible block of silicon covered with glass and using chemical vapor deposition to grow MoS.2 one layer of atoms at a time until it is three atoms thick.
This layering technique forms and cools critical parts on rigid silicon, allowing Stanford researchers to apply the flexible material at temperatures up to 850 ° C without damaging the substrate. A follow-up bath in deionized water causes the device to peel off the substrate and form a fully flexible polyimide. The final structure, including the polyimide, is only 5 microns thick, about 10 times thinner than a human hair.
Through this new process, might be of interest to those working in the field of flexible electronics, a question to what extent it is possible to further integrate flexible electronics into real world applications and devices?
Is Samsung opening the door to mass production?
As stated earlier, one of the biggest challenges in flexible electronics is the manufacturing process. This process can make it difficult to mass produce or implement the process into existing systems.
However, this month, Samsung published a new article in which they detail how they were able to create a new flexible portable device, which indicates that it can be integrated into pre-existing semiconductor processes. This innovation could help bring the concept of flexible electronics closer to mass production.
The new device integrates an expandable OLED display and photoplethysmography (PPG) sensor into a single flexible unit capable of measuring and displaying the user’s heart rate in real time, creating, what the researchers call, a “skin.” expandable electronics ”. Capable of undergoing up to 30% deformation without any decrease in performance, this device claims to be able to stretch over 1000 times without a problem.
The diagrams (A) and (B) the photograph of the extensible “skin” device. Image of Chung et al and Samsung
To create a screen that could undergo stretching and deformation without loss of performance, researchers needed to ensure that all materials and elements, including the substrate, electrode, thin film transistor, layer of material, and emission and sensor, were also stretchable. For this, Samsung researchers have chosen to replace the plastic material of existing expandable screens with an elastomer.
Elastomers are vulnerable to heat, and to mitigate this, researchers physically altered the thermal resistance of the material by adjusting its molecular composition and chemically integrating certain chains of molecules to establish resistance to materials used in semiconductor processes. .
Additionally, by using an “island structure”, the researchers were able to divert the felt stresses from the screen to the elastomer, which minimized the stress on the more fragile OLED pixel area.
A flexible future
Samsung and Stanford have both worked to address the manufacturing challenges associated with flexible electronics, and both have achieved seemingly impressive results.
While there are still many challenges when it comes to flexible electronics, there is a lot of progress being made in universities, which hopefully provides enough evidence that this technology may soon come to fruition.
Interested in other flexible electronic news? Find the articles below.
Micro-LED vs OLED: what future for foldable screens?
Keep portable devices cool: Non-metallic materials give off heat from users, circuitry, and sunlight
Developing foldable and fully flexible electronics with a new class of films