Andrea di Matteo

Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems

We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.

A Photolithographic Approach to Polymeric Microneedles Array Fabrication

In this work, two procedures for fabrication of polymeric microneedles based on direct photolithography, without any etching or molding process, are reported. Polyethylene glycol (average molecular weight 250 Da), casted into a silicone vessel and exposed to ultraviolet light (365 nm) through a mask, cross-links when added by a commercial photocatalyzer. By changing the position of the microneedles support with respect to the vessel, different shapes and lengths can be achieved. Microneedles from a hundred microns up to two millimeters have been obtained just tuning the radiation dose, by changing the exposure time (5–15 s) and/or the power density (9–18 mW/cm2) during photolithography. Different microneedle shapes, such as cylindrical, conic or lancet-like, for specific applications such as micro-indentation or drug delivery, are demonstrated.

New insights into oxidation properties and band structure of fluorescein dyes from ab initio calculations

During recent years, several publications have investigated the electrical bistability of spin cast films of halogenated fluorescein dyes. In the present contribution, we simulate the excited states of single fluorescein dyes with time-dependent density functional theory (TD-DFT) and we analyzed the band structure of the corresponding molecular crystals with DFT. More precisely, the molecules examined are fluorescein, erythrosine B, and rose bengal. We consider the molecular crystals of fluorescein in salt and lactone forms as well as erythrosine B. Rose bengal showed high quantum yield of the triplet state and high electronic affinity. Therefore, the rose bengal has very strong oxidation properties and it is able to form electrically bistable thin oxide layer. The poor crystal order and small bandwidths of fluorescein in salt form and erythrosine B indicated high resistivity for both crystals.