Electrochemical mechanical micromachining based on confined etchant layer technique

National Science Foundation of China [91023006, 91023047, 91023043, 21061120456, 21021002]; Natural Science Foundation of Fujian Province of China [2012J06004]; Fundamental Research Funds for the Central Universities [2010121022]; Scientific Research Foundation for the Returned Overseas Chinese Scholars (State Education Ministry)The confined etchant layer technique (CELT) has been proved an effective electrochemical microfabrication method since its first publication at Faraday Discussions in 1992. Recently, we have developed CELT as an electrochemical mechanical micromachining (ECMM) method by replacing the cutting tool used in conventional mechanical machining with an electrode, which can perform lathing, planing and polishing. Through the coupling between the electrochemically induced chemical etching processes and mechanical motion, ECMM can also obtain a regular surface in one step. Taking advantage of CELT, machining tolerance and surface roughness can reach micro-or nano-meter scale

Ang-(1–7) inhibited mitochondrial fission in high-glucose-induced podocytes by upregulation of miR-30a and downregulation of Drp1 and p53

Background: The aim of this study was to investigate the possible effects of angiotensin-(1–7) [Ang-(1–7)] on podocytes and the mitochondrial signaling pathway in a high-glucose (HG) environment. Methods: We established a model of HG-induced podocytes by incubating podocytes in RPMI 1640 containing 33mM glucose. The cells were divided into the following groups: (1) normal glucose group as control incubated in Roswell Park Memorial Institute (RPMI) 1640 containing 5mM glucose; (2) Ang-(1–7), 10nM, incubated in RPMI 1640 containing 5mM glucose; (3) the HG group incubated in RPMI 1640 containing 33mM glucose; and (4) Ang-(1–7), 10nM, incubated in HG group incubated in RPMI 1640 containing 33mM glucose. After a period of 24 hours, mitochondrial fission and podocyte fusion were observed by electron microscope. Additionally, p53 and Drp1 were tested by Western blot, the position of Drp1 was detected by immunofluorescence, and miR-30a was analyzed by quantitative real-time polymerase chain reaction. Results: Ang-(1–7) inhibited mitochondrial fission in HG-treated podocytes. However, Ang-(1–7) also significantly reduced the expression of Drp1 and p53, and improved the expression of miR-30a in HG-induced podocytes. Conclusion: Ang-(1–7) inhibited mitochondrial fission in HG-induced podocytes by upregulation of miR-30a and downregulation of Drp1 and p53

Generation/collection mode of SECM with combined probe

National Natural Science Foundation of China [20973142]; NSFC Innovation Group of Interfacial Electrochemistry [21021002]; Xiamen UniversityHere we report a novel generation/collection operation mode of scanning electrochemical microscopy, in which a theta micropipette was employed to support two adjacent water/1,2-dichloroethane interfaces separated by the thin central glass wall: one acts as the generator while the other as the collector. The generation current, collection current and collection efficiency were enhanced significantly when the tip approached to an insulate substrate. (C) 2011 Dong Ping Zhan. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved

Solid-State Redox Solutions: Microfabrication and Electrochemistry

National Science Foundation of China (NSFC)[20973142]; NSFC Innovation Group of Interfacial Electrochmistry[21021002]; National Project 985 of High Education; New Faculty Starting Package of Xiamen Universit

Electrochemical Storage of Atomic Hydrogen on Single Layer Graphene

International audienceIf hydrogen can be stored and carried safely at a high density, hydrogen-fuel cells offer effective solutions for vehicles. The stable chemisorption of atomic hydrogen on single layer graphene (SLG) seems a perfect solution in this regard, with a theoretical maximum storage capacity of 7.7 wt %. However, generating hydrogenated graphene from H2 requires extreme temperatures and pressures. Alternatively, hydrogen adatoms can easily be produced under mild conditions by the electroreduction of protons in solid/liquid systems. Graphene is electrochemically inert for this reaction, but H-chemisorption on SLG can be carried out under mild conditions via a novel Pt-electrocatalyzed "spillover-surface diffusion-chemisorption" mechanism, as we demonstrate using dynamic electrochemistry and isotopic Raman spectroscopy. The apparent surface diffusion coefficient (∼10-5 cm2 s-1), capacity (∼6.6 wt %, ∼85.7% surface coverage), and stability of hydrogen adatoms on SLG at room temperature and atmospheric pressure are significant, and they are perfectly suited for applications involving stored hydrogen atoms on graphene

Electrochemical regulation of the band gap of single layer graphene: from semimetal to semiconductor

As a semimetal with a zero band gap and single-atom-scale thickness, single layer graphene (SLG) has excellent electron conductivity on its basal plane. If the band gap could be opened and regulated controllably, SLG would behave as a semiconductor. That means electronic elements or even electronic circuits with single-atom thickness could be expected to be printed on a wafer-scale SLG substrate, which would bring about a revolution in Moore's law of integrated circuits, not by decreasing the feature size of line width, but by piling up the atomic-scale-thickness of an SLG circuit board layer by layer. Employing scanning electrochemical microscopy (SECM), we have demonstrated that the electrochemically induced brominating addition reaction can open and regulate the band gap of SLG by forming SLG bromide (SLGBr). The SLG/SLGBr/SLG Schottky junction shows excellent performance in current rectification, and the rectification potential region can be regulated by tuning the degree of bromination of SLG. This work provides a feasible and effective way to regulate the band gap of SLG, which would open new applications for SLG in micro–nano electronics and ultra-large-scale integrated circuits (ULSI)

Combinatorial Screening of Photoelectrocatalytic System with High Signal/Noise Ratio

Solar energy is the most abundant nature resource and plays important roles in the sustainable developments of energy and environment. Scanning photoelectrochemical microscopy provides a high-throughput screening method by introducing the combinatorial technique to prepare the substrate with photoelectrochemical catalyst array. However, the signal/noise (S/N) ratio suffers from the background current of indium–tin oxide or fluorine-doped tin oxide itself, including a transient charge–discharge current of electric double layer and a steady-state photocatalytic current. Here we adopt a facile microfabrication method to isolate the substrate area other than the catalyst array from not only the electrolyte solution but also the light illumination. Consequently, the imaging quality has been promoted dramatically due to suppressed background current. This method provides a high S/N ratio screening method, which will be valuable for the high-throughput optimization of the photoelectrocatalytic system

Combinatorial screening of photoelectrocatalytic system with high signal/noise ratio

Solar energy is the most abundant nature resource and plays important roles in the sustainable developments of energy and environment. Scanning photoelectrochemical microscopy provides a high-throughput screening method by introducing the combinatorial technique to prepare the substrate with photoelectrochemical catalyst array. However, the signal/noise (S/N) ratio suffers from the background current of indium-tin oxide or fluorine-doped tin oxide itself, including a transient charge-discharge current of electric double layer and a steady-state photocatalytic current. Here we adopt a facile microfabrication method to isolate the substrate area other than the catalyst array from not only the electrolyte solution but also the light illumination. Consequently, the imaging quality has been promoted dramatically due to suppressed background current. This method provides a high S/N ratio screening method, which will be valuable for the high-throughput optimization of the photoelectrocatalytic system. (Figure Presented)