There have been some interesting reports in the last year that indicate there is a growth in interest and a branching out in nanomaterials research. In the pursuit of increasing the capability of better batteries, researchers are investigating many different ideas. One on them if from a collaboration between University College London and the University of Chicago. They reported on work to a magnesium battery. [Ref. 1] This effort is to produce batteries with materials other than Lithium is based on the concern that the technology is reaching a limit of its capabilities along with the potential fire causation due to short circuiting. Magnesium batteries currently are being limited by the lack of inorganic materials that will work. The researchers employed different techniques to produce an ordered 7nm magnesium particle. What they found is that a disordered arrangement of 5nm particles has an ability to recharge more quickly. It is thought that the disordered arrangement is what permits the recharging of the battery, which the arrangement of ordered crystals does not permit. This opens up a new area of investigation for many types of materials.
Work at New York University Tandon School or Engineering and NYC Center for Neural Science on electrochemical sensors are based on graphene. [Ref. 2] Their work on developing a graphene sensor with predictable properties focused on the atomic level. The history of graphene applications show that large scale requirements are normally hindered by defects. Defect-free graphene on a large scale has not been demonstrated. It is known that the defects in graphene can change the properties of the material. This work is directed at trying to understand the relationship between various defects and the graphene electrical properties. The intent is to develop a means of predicting the capabilities of the sensor based on the placement and type of the defect.
Work at the University of Pennsylvania has been focused on tungsten ditelluride. [Ref. 3] The researchers think that this material can be tuned to have different properties. Tungsten ditelluride is three atoms thick. The projection is that slightly different configurations of the atoms will produce different properties. This becomes another potential application of 2-D materials.
The Physics World “Breakthrough of the Year” award was given to Pablo Jarillo-Herrero of MIT. [Ref. 4] His work led to the discovery of “twistronics”, which is a method of fine-tuning various material properties by “twisting” (rotating) adjacent layers. A team collaborating with MIT showed that adding electrons to the “twisted” material should allow them to produce a superconducting material. There are a number of applications that theoretical physicists have indicated could be developed using this process to develop the material.
The University of Glasgow has developed a contact printing system that embeds silicon nanowires into flexible surfaces. [Ref. 5] Printing bottom-up zinc-oxide nanowires and top-down silicon nanowires. The nanowires are 115nm in diameter and spaced 165nm apart. While the size and spacing is not spectacular, the ability to print on flexible surfaces at these sizes is very interesting.
Work at the Tokyo Institute of Technology developed a molecular wire in the form of a metal electrode molecule metal electrode junction including a polyne doped with ruthenium. [Ref. 6] The key take-away is that this work is based on engineering the energy levels of the conducting orbitals of the atoms along the wire.
Based on these few examples, developments in nanomaterials, their properties, and applications are promising for this and the coming years. As theoretical efforts continue to progress, the “discovery” of material properties will continue to open new areas of research.