"Volem injectar nanorobots, guiar-los dins del cos i fer que electroestimulin texits cel·lulars o alliberin fàrmacs"

Salvador Pané, investigador de l'Institut de Robòtica i Sistemes Intel·ligents a l'ETH de Zurich, presideix l'acció europea COST E-MINDS. Ha participat en el workshop internacional e-Minds, organitzat a la UAB per la vicepresidenta de l'acció, la professora del Departament de Física Eva Pellicer. En aquesta entrevista, Pané ens introdueix en els principals reptes de la miniaturització dels dispositius electrònics, la fabricació de sistemes micro i nanoelectrònics, i ens parla del futur dels nanorobots que desenvolupa al seu laboratori de Suïssa.Salvador Pané, investigador del Instituto de Robótica y Sistemas Inteligentes en la ETH de Zurich, preside la acción europea COST E-MINDS. Ha participado en el workshop internacional e-Minds, organizado en la UAB por la vicepresidenta de la acción, la profesora del Departamento de Física Eva Pellicer. En esta entrevista, Pané nos introduce en los principales retos de la miniaturización de los dispositivos electrónicos, la fabricación de sistemas micro y nanoelectrónicos, y nos habla del futuro de los nanorobots que desarrolla en su laboratorio de Suiza.Researcher at the Institute of Robotics and Intelligent Systems of the ETH Zurich. His main tasks focus on micro and nanorobotics for biomedical applications and he specialises in electrodepositions, one of the methods used to manufacture micro and nanorobots. He is the chair of the European Union's COST E-Minds Action, one of whose objectives is to promote electrodeposition at micro and nanoscale. He participated in the e-Minds Workshop, held at the UAB and organised by the vicechair of the action, lecturer of the Department of Physics Eva Pellicer

Fabrication of sustainable hydrophobic and oleophilic pseudo-ordered macroporous Fe-Cu films with tunable composition and pore size via electrodeposition through colloidal templates

In this work, sustainable hydrophobic and oleophilic macroporous Fe-Cu films are fabricated using a straightforward, inexpensive and environmentally friendly two-step procedure which combines electrodeposition with the colloidal lithography technique. Elemental, morphological and structural characterization of the resulting pseudo-ordered meshes is carried out and wettability is assessed using contact angle measurements with respect to two distinct film compositions (3 at.% Fe vs 75-85 at.% Fe) and three different pore diameters (namely, 200 nm, 350 nm and 500 nm). Water contact angles are measured to be in the range of approximately 109.0-155.1° (without any post-surface functionalization) and a low contact angle hysteresis is observed in the superhydrophobic samples. The increase in the hydrophobic character of the films correlates well with an increase in surface roughness, whereas differences in composition play a minor role. For the superhydrophobic Fe-rich macroporous film, water-oil separation capability and recyclability are also demonstrated while the pore size is favorable for effective water-oil mixture and emulsion separation. The results shown here demonstrate that sustainable and affordable materials processed in a simple and cheap manner can be an asset for the removal of water-immiscible organic compounds from aqueous environments

Mechanical Properties and Corrosion Behaviour of Nanostructured Cu-rich CuNi Electrodeposited Films

Nanocrystalline Cu-rich CuNi alloy thin films (with copper content ranging from 22 to 97 at%) have been grown by electrodeposition, using galvanostatic conditions in an electrolytic bath containing Ni and Cu sulphates with a [Ni(II)]/[Cu(II)] molar ratio of 11. The Cu content is tuned by varying the applied current density during deposition. The nanoscrystalline nature of Cu-rich CuNi thin films has been achieved using saccharine as a grain refinement agent, although for high Cu content (> 90 at%) the refinement effect is less pronounced. Due to the nanocrystalline character of the films, low surface roughness, good compactness, and outstanding mechanical properties (e.g. nanoindentation hardness values off approximately 7 GPa) are obtained, particularly for Cu percentages below 70 at%. The presence of stacking faults also contributes to the observed high strength. The films show good corrosion protective behaviour in a 3.5 wt% NaCl medium, with corrosion potentials more positive than the bare substrate (pure-Cu) and lower corrosion current density values ranging from 1.8 to 5.4 [mi]A/square centimeter

A comparison between fine-grained and nanocrystalline electrodeposited Cu-Ni films. Insights on mechanical and corrosion performance

This is the author's version of a work that was accepted for publication in Surface & coating technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Surface & coating technology, Vol. 205, Núm. 23-24 (Sep 2011), p. 2585-5293 DOI 10.1016/j.surfcoat.2011.05.047Cu1−x-Nix (0.43 ≤ x ≤ 1.0) films were electrodeposited from citrate-sulphate baths at different current densities onto Cu/Ti/Si (100) substrates with the addition of saccharine as a grain-refining agent. The Cu-Ni alloy films produced from saccharine-free baths were fine-grained (crystallite size of ~400 nm). The addition of saccharine to the electrolytic solution induced a dramatic decrease in crystal size (down to ~27 nm) along with a reduction in surface roughness. Although the effect of saccharine on pure Ni films was less obvious, significant changes were observed due to the presence of saccharine in the bath during the alloying of Cu with Ni. Compared to fine-grained Cu-Ni films, the nanocrystalline films exhibited lower microstrains and a larger amount of stacking faults as observed by X-ray diffraction. These features enhance the mechanical properties of the Cu-Ni alloys, making the nanocrystalline Cu-Ni films superior to both the corresponding fine-grained films and pure Ni films. In particular, hardness in fine-grained films varied from 4.2 (x=0.43) to 5.4 GPa (x=0.86), whereas hardness varied between 6.7 and 8.2 GPa for nanocrystalline films of similar composition. In addition, wear resistance and elastic recovery were enhanced. Nanostructuring did not significantly affect corrosion resistance of Cu-Ni alloys in chloride media. Although the corrosion potential shifted slightly towards more negative values, the corrosion current density decreased, thereby making the electrodeposition nanostructuring process an effective tool to improve the overall properties of the Cu-Ni system

Magnetometry of individual polycrystalline ferromagnetic nanowires

Ferromagnetic nanowires are finding use as untethered sensors and actuators for probing micro- and nanoscale biophysical phenomena, such as for localized sensing and application of forces and torques on biological samples, for tissue heating through magnetic hyperthermia, and for micro-rheology. Quantifying the magnetic properties of individual isolated nanowires is crucial for such applications. We use dynamic cantilever magnetometry to measure the magnetic properties of individual sub-500nm diameter polycrystalline nanowires of Ni and Ni80Co20 fabricated by template-assisted electrochemical deposition. The values are compared with bulk, ensemble measurements when the nanowires are still embedded within their growth matrix. We find that single-particle and ensemble measurements of nanowires yield significantly different results that reflect inter-nanowire interactions and chemical modifications of the sample during the release process from the growth matrix. The results highlight the importance of performing single-particle characterization for objects that will be used as individual magnetic nanoactuators or nanosensors in biomedical applications

Localized electrochemical deposition of porous Cu-Ni microcolumns: insights into the growth mechanisms and the mechanical performance

Cu-rich Cu-Ni alloy microcolumns (11-35 at% Ni) with large porosity degree were grown by localized electrochemical deposition (LECD) at voltages of 6.5 and 7.0 V. In turn, conventional electrodeposition was used to deposit fully-compact Cu-Ni films with analogous Ni/Cu ratios from a similar citrate-containing electrolytic solution. The localized supply rate of the predominant Cu(II) and Ni(II) electroactive species in the LECD microregion was calculated assuming both large and small concentration gradients. A shortage of Cu(II) at the cathode surface is mainly responsible for the development of porosity in the microcolumns, which directly affects mechanical performance, specifically nanoindentation hardness and Young's modulus. From nanoindentation experiments, a relative microcolumn density ranging between 14 and 20% was determined. These values indicate the current efficiency of the LECD process and can be used to calculate the consumption rates associated with metal cation electroreduction

Tailoring the physical properties of electrodeposited CoNiReP alloys with large Re content by direct, pulse, and reverse pulse current techniques

This is the author's version of a work that was accepted for publication in Electrochimica acta. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Electrochimica acta, [96,(2013)] DOI10.1016/j.electacta.2013.02.077)The composition, surface morphology and structure of CoNiReP alloy films with large Re content (up to 27 at%), obtained in a citrate-glycine based electrolyte have been studied as a function of the electrodeposition technique. Direct current (DC), pulse plating (PP) and reverse pulse plating (RPP) were considered with cathodic current densities from −50 mA cm−2 to −250 mA cm−2. The mechanical and magnetic properties have been analyzed and the data obtained has been correlated with composition and crystallographic structure. For values of j (DC), jon (PP) and jc (RPP) below −100 mA cm−2, Co-rich, P-containing deposits are obtained. Beyond these current densities, both the quantities of Ni and Re increase simultaneously at the expense of Co and P, the latter virtually falling to zero. The highest Re percentage (25-27 at%) was achieved in both PP and RPP conditions at a cathodic pulse of −250 mA cm−2. All the films were either entirely nanocrystalline in nature or partially amorphous. Hardness values as high as 9.2 GPa have been found in PP plated Co64Ni18Re18 deposits. Besides the large hardness, the incorporation of Re in the films leads to high elastic recovery values. The magnetic character of the deposits ranges from soft to semi-hard ferromagneti

Micelle-assisted electrodeposition of mesoporous Fe-Pt smooth thin films onto various substrates and their electrocatalytic activity towards hydrogen evolution reaction

Mesoporous Fe-Pt thin films are obtained by micelle-assisted electrodeposition onto metallic substrates with dissimilar activity (namely, gold, copper, and aluminum seed layers evaporated on Si/Ti) under constant applied potential (E=-1.1 V vs. Ag/AgCl) and deposition time (600 s). The amphiphilic triblock copolymer Pluronic P-123 is used as a soft template to guide the formation of mesopores. The occurrence of pores (ca. 7 nm in diameter) with narrow size distribution, distributed evenly over the surface, is observed in all cases. Despite the applied conditions being the same, the roughness and the amount of Fe incorporated in the films are influenced by the nature of the substrate. In particular, ultra-smooth films containing a larger amount of Fe (21 wt %) are obtained when deposition takes place on the Au surface. X-ray diffraction analyses reveal that Pt and Fe are alloyed to a certain extent, although some iron oxides/hydroxides also unavoidably form. The resulting films have been tested as electrocatalysts in the hydrogen evolution reaction (HER) in alkaline media. The mesoporous Fe-rich Fe-Pt films on Au show excellent HER activity and cyclability

Electrodeposition of sizeable and compositionally tunable rhodium-iron nanoparticles and their activity toward hydrogen evolution reaction

Rh-Fe nanoparticles (NPs) with variable Rh/Fe ratios have been obtained by direct current electrodeposition onto Au-metalized Si/Ti substrates from an electrolyte containing Rh(III) and Fe(III) chloride salts. NP mean diameter could be varied in the range of 20-80 nm by playing with the applied current density (-j = 0.5-2 mA cm-2) and deposition times (t = 200-3200 s). NPs were very well adhered to the substrate and became progressively enriched in Fe as the absolute value of the current density increased. X-ray photoelectron spectroscopy analyses revealed that the NPs are mostly metallic. The oxygen signal detected at surface level is relatively high but reduces down to less than 1 at% after 1 min Ar ions sputtering. The as-deposited Rh-Fe NPs are active toward hydrogen evolution reaction in alkaline medium. Different values of the onset potential for water reduction have been observed depending on the j and t values applied for NPs growth. Cycling stability tests reveal that NPs do not suffer from excessive deterioration of their electrocatalytic activity with time

One-pot electrosynthesis of multi-layered magnetic metallopolymer nanocomposites

Researchers have been investigating various methodologies for fabricating well-defined, homogenous composites consisting of nanoparticles (NPs) dispersed in a matrix. The main challenges are to prevent particle agglomerations during fabrication and to obtain nanoparticles whose size distribution could be tuned on demand. One of the methods that can provide these features is electrodeposition. We report for the first time the fabrication of a thin magnetic multilayer nanocomposite film by electrodeposition from one bath containing both a monomer and metal salts. Cobalt and cobalt-nickel NPs were deposited on conductive polymer polypyrrole thin films using different electrodeposition potentials and times. Multilayer nanocomposite films were fabricated by subsequent electrodeposition of polymer and nanoparticle layers. Scanning electron microscopy analysis showed that a wide range of NPs (70-230 nm) could be synthesized by manipulating growth potentials and times. The cobalt-nickel NPs were found to contain hexagonal close-packed (hcp) and face-centered cubic (fcc) phases based on X-ray diffraction and selected area electron diffraction. Magnetic measurements proved that both the single and the multi-layered nanocomposites were magnetic at room temperature