The plasma facing components, first wall, and blanket systems of future tokamak-based fusion power plants arguably represent the single greatest materials engineering challenge of all time. Indeed, the United States National Academy of Engineering has recently ranked the quest for fusion as one of the top grand challenges for engineering in the 21st century. These challenges are even more pronounced by the lack of experimental testing facilities that replicate the extreme operating environment involving simultaneous high heat and particle fluxes, large time-varying stresses, corrosive chemical environments, and large fluxes of 14-MeV peaked fusion neutrons. Fortunately, recent innovations in computational modeling techniques, increasingly powerful high-performance and massively parallel computing platforms, and improved analytical experimental characterization tools provide the means to develop self-consistent, experimentally validated models of materials performance and degradation in the fusion energy environment. This article will describe the challenges associated with modeling the performance of plasma facing component and structural materials in a fusion materials environment, the opportunities to utilize high-performance computing, and two examples of recent progress.

Graphene has been known for a long time, but only recently has its potential for electronics been recognized. Its history is recalled starting from early graphene studies. A critical insight in June 2001 brought to light that graphene could be used for electronics. This was followed by a series of proposals and measurements cumulating in a comprehensive patent for graphene-based electronics filed in 2003. The Georgia Institute of Technology (GIT) graphene electronics research project group selected epitaxial graphene as the most viable route for graphene-based electronics, as described in their 2004 paper on transport and structural measurements of epitaxial graphene. Subsequently, the field developed rapidly, and multilayer graphene was discovered at GIT. This material consists of many graphene layers, but it is not graphite; in contrast to graphite, the layers are rotated with respect to each other, causing electronic decoupling so that each layer has the electronic structure of graphene. Currently, the field has developed to the point where epitaxial graphene-based electronics may be realized in the not too distant future.

Introducing micro- and nanoscale features on biomaterials in an engineered, controlled manner has been shown to positively affect medical implant integration into the human body. A key factor in this process is the initial cellular response toward the implant. Different techniques such as chemical treatment, plasma spraying, lithography, and coatings, among others, have been applied during the last decades to improve the implant integration. One of the methods that started to be recently exploited is laser surface engineering (LSE). LSE offers a wide range of new surface engineering methods, such as laser surface melting (LSM), laser engineered net shaping (LENS), and selective laser melting/sintering (SLM/S) that can generate complex micro- and nanoscale features with high resolution. This review provides an overview of the initial cellular response to medical implants and the different techniques used to modify the surface of different biomaterials. An emphasis is given to laser techniques that were recently developed for surface texturing, describing in vitro, pre-clinical, and clinical trials performed thus far.

Dissimilatory metal-reducing bacteria (DMRB) are a fascinating group of microorganisms that inhabit many natural environments. They possess a distinct capability wherein they can acquire energy by coupling oxidation of organic matter with reduction of insoluble oxidants such as mineral deposits. This capability requires that DMRB transfer respired electrons to their outer surface where electron transfer can occur to an insoluble oxidant. This is distinct from the dominant paradigm, wherein soluble oxidants are transported into microbes for reduction during metabolism. This unique extracellular electron transfer (EET) capability of DMRB extends to reduction of electrodes on which they can proliferate and form persistent films (biofilms). This capability makes DMRB useful as anode catalysts in microbial fuel cells for alternative energy generation and for degradation of organic wastes. In the case of Geobacter spp., anode biofilms can grow to be many microbes thick. In such biofilms, individual microbes contribute to a flux of electrons to the underlying electrode surface, which may be many cell lengths away, confounding long-held notions about the inability of microbes to engage in such long-range EET. This article describes the electrode-reducing ability of DMRB and the latest results describing the mechanism of long-range extracellular electron transfer, which appears to involve filamentous appendages termed nanowires.

Controlling the spatial arrangement of biomaterials, including living cells, with high resolution (±5 μm) provides the foundation for fabricating complex biologic systems for studies ranging from the fundamentals of cell-cell and cell-matrix interactions to applications in tissue engineering. However, the level of spatial control required cannot be obtained through conventional cell processing techniques (e.g., pipetting of or even ink-jetting cells), as they lack the precision, reproducibility, and speed required for the rapid fabrication of idealized engineered constructs. Laser direct-write approaches (e.g., matrix-assisted pulsed-laser evaporation direct-write [MAPLE DW]), previously employed for the rapid prototyping of electronics, have shown reliable patterning of biomaterials with a spatial resolution of ±5 μm. Moreover, recent advances allow the rapid, precise deposition of viable mammalian cells and pluripotent stem cells on well-defined substrates, enabling the laser direct-writing platform to advance manipulation of the in vitro cellular microenvironment (e.g., the stem cell niche). Herein, we review the mechanisms and recent advances demonstrating the versatility and biofabrication potential of one particular laser-based technique, MAPLE DW.