Fabio Di Pietrantonio

Carbon nanostructures are achieved by bio-waste Allium cepa, L., (onion vulgaris) peels through pyrolysis at 900 °C. They contain dispersed elements derived by their bio-precursors, like Mg, Ca, S, Na, K, and Cu. Here, we report the self-assembly of new Cu flower-shaped nanostructures organized as nano-roses. Remarkably, the nano-roses show rolled-up petals of Cu⁰ with a high chemical stability in air, exhibiting an intrinsic pure Cu crystalline phase. This suggests the exceptional potentiality to synthesize Cu⁰ nanostructures with novel physical/chemical properties. The size, morphology, and chemical composition were obtained by a combination of high-resolution scanning electron microscopy, energy dispersive X-ray spectroscopy, energy dispersive X-ray diffraction, and Raman spectroscopy.

Among the many biological effects caused by low intensity extremely high frequency electromagnetic fields (EHF-EMF) reported in the literature, those on the nervous system are a promising area for further research. The mechanisms by which these fields alter neural activity are still unclear and thus far there appears to be no frequency dependence regarding neuronal responses. Therefore, properin vitromodels for preliminary screening studies of the interaction between neural cells with EMF are needed. We designed an artificial axon model consisting of a series of parallel RC networks. Each RC network contained an aqueous solution of lipid vesicles with a gradient of potassium (K⁺) concentration as the functional element. We investigated the effects of EHF-EMF (53.37 GHz–39 mW) on the propagation of the electric impulse. We report that exposure to the EHF-EMF increases the amplitude of electrical signal by inducing a potassium efflux from lipid vesicles. Further, exposure to the EHF-EMF potentiates the action of valinomycin – a K⁺carrier – increasing the extent of K⁺transport across the lipid membrane. We conclude that exposure to the EHF-EMF facilitates the electrical signal propagation by increasing transmembrane potassium efflux, and that the model presented is promising for future screening studies of different EMF frequency spectrum bands.

In this paper, a biosensor for vapor phase detection of odorant molecules based on Surface Acoustic Wave (SAW) resonators is presented. The SAW resonators were coated with a wild-type odorant-binding protein from pig (wtpOBP) deposited by laser-induced forward transfer (LIFT). Two protein solutions, i.e. with 20% and 50% (v/v) glycerol, were deposited by LIFT changing the laser fluence and the printing morphology of droplets. The SAW biosensor was tested in nitrogen upon exposure to R-(-)-1-octen-3-ol (octenol) and R-(-)-carvone (carvone) vapors in the range of concentrations between 9 and 60 ppm. An uncoated device was used to compensate the responses due to variations in environmental parameters. The differential response curves showed a linear behavior in the tested range of concentrations and the obtained sensitivities were of 20.7 Hz/ppm and of 13.8 Hz/ppm, respectively, for octenol and carvone.

The development of organic electronic requires a non contact digital printing process. The European funded e-LIFT project investigated the possibility of using the Laser Induced Forward Transfer (LIFT) technique to address this field of applications. This process has been optimized for the deposition of functional organic and inorganic materials in liquid and solid phase, and a set of polymer dynamic release layer (DRL) has been developed to allow a safe transfer of a large range of thin films. Then, some specific applications related to the development of heterogeneous integration in organic electronics have been addressed. We demonstrated the ability of LIFT process to print thin film of organic semiconductor and to realize Organic Thin Film Transistors (OTFT) with mobilities as high as 4 10^-2 cm².V^-1.s^-1 and I_on/I_off ratio of 2.8 10⁵. Polymer Light Emitting Diodes (PLED) have been laser printed by transferring in a single step process a stack of thin films, leading to the fabrication of red, blue green PLEDs with luminance ranging from 145 cd.m^-2 to 540 cd.m^-2. Then, chemical sensors and biosensors have been fabricated by printing polymers and proteins on Surface Acoustic Wave (SAW) devices. The ability of LIFT to transfer several sensing elements on a same device with high resolution allows improving the selectivity of these sensors and biosensors. Gas sensors based on the deposition of semiconducting oxide (SnO₂) and biosensors for the detection of herbicides relying on the printing of proteins have also been realized and their performances overcome those of commercial devices. At last, we successfully laser-printed thermoelectric materials and realized microgenerators for energy harvesting applications.