What products do you normally think of when you think of trees? Paper? Lumber? Medicines, perhaps? What about phone screens? In recent years, tech companies have been trying to veer away from plastics in their electronic devices in an effort to make manufacturing more sustainable. The answer to their problem was simple: trees! Specifically, sustainably forested trees. Even more specifically, the nanocellulose obtained from microscopic tree fibers. By making phone screens out of nanocellulose–which is both biodegradable and renewable–the materials can ultimately be reused, thus promoting a circular economy of electronics and other technologies (particularly cell phones, tablets, computers, and televisions) as well as greater overall sustainability in the tech industry.
Traditional cellulose (plant fibers, especially from trees) is commonly used in foods (as a thickening agent), in medicine (as a coating or filling agent), and in different papers. What makes nanocellulose different is that the wood pulp fibers are so small and refined that you can’t even see them; when they come together, they form a flexible, transparent film much like a plastic would. Who would’ve thought that the sustainable solution to plastic electronic screens would be transparent trees? Wood, however, has been used in technology since the 1920s. When circuit boards were first being invented, fiberglass or wood pulp were commonly used to add structure to the hardware of circuit boards in computers. Since then, researchers have been studying and experimenting with wood and its various applications in devices, which is precisely what brought about nanocellulose.
There are several properties that make nanocellulose optimal in phone screen manufacturing. Firstly, it is extremely strong. Strength and durability are critical in the production of electronics. On the crystalline scale, the particles of nanocellulose are even stronger than steel. Secondly, it’s transparent. Regular cellulose has an opaqueness to it that makes it great for use in other, internal parts of electronics–the unique transparent quality of dried nanocellulose makes it a perfect plastic replacement in screens, which must be, of course, clear. In addition, nanocellulose has a low thermal expansion coefficient, meaning that heating it up will not make it expand (as it would with plastic)–this is a particularly attractive feature for tech companies due to the necessity of this quality. Furthermore, it’s extremely flexible, which is especially appealing considering the upcoming generation of foldable cell phones. To conclude, nanocellulose is generally more sustainable, given that it is sourced from sustainably-managed forests. The key benefit of nanocellulose is its biodegradability, which polymers in plastics do not offer. The manufacturing of cellulose itself is a work in progress in terms of sustainability–scientists are looking for ways to produce it using natural algae instead of chemicals that may negatively impact the environment and waterways.
As with any new technology, of course, nanocellulose has its fair share of obstacles in terms of bringing it into and diffusing it across the market. Though it has a wide range of promising qualities in its dry state, nanocellulose tends to perform more poorly in moist conditions, causing brittleness and a reduction of its aforementioned strength qualities. Additionally, the high cost of manufacturing poses a challenge in making nanocellulose more widespread–the beauty of plastic, despite its many evils, has always been its cheapness. Regardless, several companies have already implemented nanocellulose into their products. As research and further developments go into nanocellulose in technology, there is no doubt scientists will optimize the manufacturing process for nanocellulose and expand its market for greater sustainable technology throughout the world.
Written by Carole Wilay (’25)