Advanced Silicon Microstructuring by Electrochemical Micromachining: Technology and Applications

Electrochemical micromachining technology, namely ECM, is a newly proposed microstructuring technique based on electrochemical etching of n-type silicon in aqueous electrolytes containing hydrofluoric acid. Among the main features of ECM there are: i) high aspect-ratio (HAR) of feasible structures, and in turn, high integration density; ii) fine control of etching anisotropy (from 0 to 1), and in turn, enhanced flexibility in fabrication; iii) reduced roughness (about 20 nm) of etched surface. This thesis is aimed at demonstrating that ECM technology can be successfully used for the fabrication of silicon (Si) based microstructures and microsystems for a wide range of applications ranging from integrated optics, to optofluidics, from biology (3D cell culture) to synthesis of nano/micro-structured conducting polymers film. As to optics applications, for the first time, we report fabrication of a novel Si-optical platform where light from standard single mode optical fiber is directly coupled in and out high order vertical silicon/air PhCs operating in the near-infrared region. The platform consists of ECM-micromachined Si-substrate integrating an array of vertical silicon/air PhCs featuring a transmission peak at λ=1.55 μm, together with U-grooves and mechanical end-stop structures for readout optical fibers thus enabling easy-to-use and plug-and-play operation mode. As to optofluidic applications, ECM-fabricated vertical HAR-PhCs were integrated into optofluidic microsystems (OFM) together with fluidic microchannels obtained by potassium hydroxide (KOH) etching. A sensitivity value of 1049 nm/RIU at 1.55 μm and limit of detection of 10-3 RIU are obtained. Moreover, we report the successful application of ECM technology to the realization of all-silicon OFMs in which HAR-PhCs are integrated by one-etching-step together with microfluidic reservoirs/channels and fiber grooves, for alignment/positioning of readout optical fibers in front of the PhC. Assessment of this OFM as refractive index sensor was also performed. High sensitivity of 670 nm/RIU at 1.55 μm and good limit of detection of about 10-3of PhC-OFMs were obtained. As to 3D cell culture applications, we have demonstrated ECM-fabrication of in vitro 3D-microincubators featuring HAR Si-microstructures for mesenchymal cells culturing. In particular, the proposed microincubator selects mesenchymal cells that show the ability to grow in the gaps between two adjacent HAR silicon walls. Finally, we have developed a novel technology for microstructuring polypyrrole (PPy) films based on light-activated PPy electrosynthesis on ECM-micromachined Si-substrates. Scanning electron microscopy highlights as light-activation allows a highly conformal polymer growth yielding a 3D-PPy structure perfectly replicating the Si microstructure

First Record of Eurasian Spoonbills Platalea leucorodia feeding on Branchiopoda in a temporary wetland

The diet of the Eurasian Spoonbill Platalea leucorodia is poorly documented with only the most common prey groups known, namely small fishes, amphibians, reptiles, crustaceans, molluscs, worms, leeches and plant material. Here, the first observations of three small crustaceans, Branchiopoda Triops cancriformis (Notostraca), Chirocephalus diaphanus (Anostraca), and Cyzicus tetracerus (Spinicaudata) are documented as prey of the Eurasian Spoonbill in a temporary wetland near the San Teodoro salt pan (Marsala, western Sicily). These observations provide a new insight into the foraging ecology of the species, showing its extreme opportunism in targeting small prey when feeding in a temporary wetland system

3. Eurasian Thick-knee Burhinus oedicnemus

Eurasian Thick-knee Burhinus oedicnemu

New data on Calomera panormitana panormitana (Ragusa, 1906) in Sicily (Coleoptera Cicindelidae)

Calomera panormitana panormitana (Ragusa, 1906) (Coleoptera Cicindelidae) is an endemic species of Sicily, of remarkable biogeographic and ecological importance. It belongs to a small group of species of eastern Mediterranean distribution and it is peculiar for living on the low rocky coasts, near the sea. In this paper we provide new and summarized data on the presence of this species in Sicily. We examined its habitat, ecology and phenology in detail, and we provide useful elements for a better protection. In particular, the presence of this species also in some small islands, located at a short distance from the coast, highlights the presence of important refuge areas to be protected and promoted

Sulla distribuzione di alcuni Uccelli nidificanti in provincia di Trapani (Sicilia)

A distanza di 10 anni dalla pubblicazione dell’ultimo Atlante dei Vertebrati di Sicilia si rivede la distribuzione delle specie nidificanti, alla luce di nuovi dati raccolti, al fine di aggiornare il loro status. Nel presente lavoro vengono elencate solo le specie di uccelli, rilevate in questi ultimi anni, non segnalate come nidificanti nei precedenti Atlanti e le specie già trattate ma che hanno riportato delle variazioni significative nella loro distribuzione.Updating of the distribution of some breeding birds in the province of Trapani (Sicily). This work deals with the distribution of the breeding birds in the province of Trapani (western Sicily); here are provided and updated the status of birds on the basis of data collected since the 2013, after the publication of the last Sicilian Atlas of Vertebrates. The present work lists exclusively the species observed in the last years, not found as breeding in the previous Atlases, and the species which, although mentioned in the previous Atlases, underwent a significant variation in their distribution

OSSERVAZIONI DI ZYGONYX TORRIDUS (KIRBY 1889) (Insecta Odonata) IN ITALIA

Records of Zygonyx torridus (Kirby 1889) (Insecta Odonata) in Italy

Passero Passer italiae x hispaniolensis nidificante su barca da pesca in Sicilia

This short note reports the curious breeding, in terms of nest features, of several Sparrows mainly showing the phenotype of the Spanish Sparrow or Passer prope hispaniolensis, though, few males exhibited less barred flanks as for the Passer italiae. This is in agre- ement with the ambiguous taxonomy of Sparrows of Sicily that is emerged over the past 150 years. As matter of fact, the taxonomic classification of the Sicilian sparrow spans from Passer hispaniolen- sis to Passer italiae and includes hybrid species in between. Massa et al (2022) propose to name these populations Passer italiae x hispa- niolensis. Here, for the first time, the curious nesting of Passer prope hispa- niolensis on Ligurian fishing boats (gozzi) moored at Margi Spanò near Petrosino (western Sicily) is reported and discussed. Such behavior has been already observed for aquatic species belonging to the families of Anatidae, Sulidae and Rallidae, but it represents unusual behavior for Passeriformes. It is worth noting that, among the observed individuals, at least 12 pairs of Sparrow used five different moored boats as nesting sites. Nest predation has a strong impact on the reproductive success of birds. The choice of nesting on boats might represent a strategy the sparrow intentionally adopted to increase their fledging and, hence, sur- vival rate

Printability conditions for an all-solid-state laser transfer

Several laser technologies exist capable of adding solid materials to a targeted area of a substrate, including photopolymerization, laser sintering, or laser-induced forward transfer. However, the added material normally undergoes a phase change, causing adverse effects such as shrinkage, stress, or degradation. As recently demonstrated, this issue can be addressed by using laser pulses to mechanically delaminate and eject a disk from a solid film. In this case, the laser plays the role of a catapult, with minimal thermal damage to the transferred disk. Despite proven success in micro-electronics and micro-optics, little is known about the mechanical properties of the film that lead to a crack-free all-solid-state transfer. Here, we present a theoretical and experimental study on the effects that film rigidity, elasticity, and plasticity play on laser catapulting. By combining the thermodynamic equations of the laser-generated propulsion force with the theory of thin plate bending, we derived an analytical model that fully describes the list of events responsible for disk ejection. The model is in good agreement with experiments using elastomers, polymers, and metals. A complete printability map based on the film mechanical parameters is reported, which can help to broaden the family of materials suitable for laser additive manufacturing

On the presence of the alien exotic sap beetle Phenolia (Lasiodites) picta (Macleay, 1825) (Coleoptera Nitidulidae) in Italy

The exotic sap beetle Phenolia (Lasiodites) picta (W.S. Macleay, 1825) (Coleoptera Nitidulidae) is an alien species recently recorded in Europe (Spain, France, and Greece), and Turkey. For Italy, only a single record of P. cf. picta is reported from Sicily. In this paper, we studied this specimen confirming the presence of P. picta in Italy

Nanopatterning with Photonic Nanojets: Review and Perspectives in Biomedical Research

: Nanostructured surfaces and devices offer astounding possibilities for biomedical research, including cellular and molecular biology, diagnostics, and therapeutics. However, the wide implementation of these systems is currently limited by the lack of cost-effective and easy-to-use nanopatterning tools. A promising solution is to use optical methods based on photonic nanojets, namely, needle-like beams featuring a nanometric width. In this review, we survey the physics, engineering strategies, and recent implementations of photonic nanojets for high-throughput generation of arbitrary nanopatterns, along with applications in optics, electronics, mechanics, and biosensing. An outlook of the potential impact of nanopatterning technologies based on photonic nanojets in several relevant biomedical areas is also provide