Graphene is continuing to earn its reputation as a thing of "wonder." Explore a handful of recent studies that are pushing the boundaries of this exciting material.
Graphene is a one-atom thick layer of carbon atoms in a two-dimensional hexagonal lattice. It was first isolated in 2004 and quickly earned its pioneers a Nobel Prize. Since then, this remarkable substance has been investigated for a number of uses. Here, we showcase a handful of recent publications that are pushing the boundaries of this exciting material.
Faster Fire Detection
In the event of a fire, time is of the essence—but traditional smoke-activated fire detectors often take more than 100 seconds to sound an alarm. A recent study in ACS Applied Materials & Interfaces demonstrates the potential of graphene as an effective material for quicker, more reliable fire detection due to its high electron mobility, superior thermal conductivity, high mechanical properties, and structural stability under high temperatures.
The authors constructed a graphene-based composite alarm that was able to provide a response in under 5 seconds. Furthermore, their results suggest that the graphene ratio can be tuned to achieve different response temperatures and sensitivity, which may allow for life-saving customization in different fire-prone scenarios.
Read the full article: Tunable Graphene/Nitrocellulose Temperature Alarm Sensors
An Energy-Saving Heat Source
Work published in ACS Nano explores a new method of radiant heating using a lightweight, flexible dual-emitter graphene glass fiber. Thermal radiation has been developed for a range of applications including thermal energy harvesting, infrared detection, and communications. Metal alloys such as nichrome are often used for radiant heating, but they have limited infrared radiation characteristics, and are also rigid and heavy. Compared to these traditional alloy heating wires, graphene glass fiber showed superior radiant heating capability—and with energy savings of more than 30%.
Read the full article: Dual-Emitter Graphene Glass Fiber Fabric for Radiant Heating
Improving Rechargeable Battery Performance
As well as saving energy, graphene may also be used for energy storage. High conductivity makes graphene cathodes an attractive option in rechargeable aluminum-ion batteries. This use isn’t new, but fabricating high-quality and low-defect graphene cathodes via typical methods is both tedious and energy-consuming.
With this in mind, researchers set out to improve upon current methods by developing a simple microwave-reduction method of fabrication. The authors built a cathode made from graphene oxide using the modified Hummers’ method—with fibers from the oxide suspension synthesized by syringe pump injection and microwave reduction. The results demonstrated increased storage, a stable discharge capacity, and an impressive ability to withstand more than 4,500 charge cycles without decay.
Read the full article: Microwave-Reduced Graphene Oxide for Aluminum Batteries
Big Potential for Tiny Mics
As many of our modern electronic devices continue to shrink in size, their components—for example, microphones—must also follow suit without losing quality. Graphene is proving to be more than fit for the role, where its flexibility, strength, nanometer thinness, and high electrical conductivity are paramount. One recent study reveals a transfer-free method to construct wafer-thin graphene "drums" by growing and releasing graphene on a silicon substrate. The authors report that the tiny graphene drums demonstrated much higher sound detection sensitivity compared to most commercial MEMS microphones, while taking up about a tenth of the space.
Read the full article: Sensitive Transfer-Free Wafer-Scale Graphene Microphones
The key attributes of this fascinating material could also offer biomedical breakthroughs by allowing the development of robust and biocompatible porous structures. Graphene hydrogels are now being investigated as the structural basis for cartilage regeneration, with results suggesting the scaffolds promote chondrocyte proliferation and remodeling of the cartilage matrix by enhancing collagen formation.
Read the full article: Graphene Hydrogel as a Porous Scaffold for Cartilage Regeneration
Greener Approaches for Graphene Synthesis
Finally, with graphene going mainstream, there will be a need for a sustainable approach to develop graphene-based materials. Natural plant-based resources and biowaste are being looked at for framing different forms of graphene—or even for the synthesis of graphene itself. A recent review in ACS Applied Electronic Materials highlights several potential natural resources that could be harnessed for this purpose, along with an overview of safer synthetic processes.
While the science is intriguing, building this facet into commercial manufacturing processes will be one of the graphene industry’s biggest challenges in the next few years. However, one thing is clear: graphene is continuing to earn its name as a wonder material.