新型聚酰亚胺图形化工艺制备视网膜电极

介绍了一种新型的、基于Cu牺牲层的聚酰亚胺图形化方法制备视网膜电极的MEMS工艺,并对其电化学性能进行了表征。该工艺创新性地以Cu作为衬底聚酰亚胺图形化的牺牲层,以PDMS(聚二甲基硅氧烷)作为剥离层,以聚酰亚胺作为封装材料,以惰性金属作为电极保护层材料,通过电铸、牺牲层和抛光打磨工艺,制备出可以自释放的柔性视网膜电极;随后,对器件进行封装,并对器件的表面形貌和电学性能进行了表征。视网膜电极器件厚度50μm,电路线宽50μm,阻抗104～105Ω。通过该工艺制得的人造视网膜电极具有柔软无伤害、生物相容以及低成本的优点。     

A novel method for sacrificial layer release in MEMS devices fabrication

During the forming process of the free-standing structure or the functional cavity when releasing the high aspect ratio sacrificial layer,such structures tend to stick to the substrate due to capillary force.This paper describes the application of pull-in length conception as design rules to a novel ’dimpled’ method in releasing sacrificial layer.Based on the conception of pull-in length in adhering phenomenon,the fabrication and releasing sacrificial layer methods using micro bumps based on the silicon substrate were presented.According to the thermal isolation performances of one kind of micro electromechanical system device thermal shear stress sensor,the sacrificial layers were validated to be successfully released.     

Su-8胶-金属复合材料电热微驱动器

针对以金属嵌入式Su-8光刻胶作为新型弯曲梁式微驱动器结构材料的特点,在仿真分析过程中,考虑了狭小空气间隙中热传导机制的影响。分析结果表明,器件的工作电压随着悬空高度的增加而降低;当悬空高度达到270μm时,可忽略热传导机制。在微加工工艺流程中,引入新的牺牲层材料,显著提升了工艺流程的兼容性和加工效果的稳定性。在此基础上研制的新型电热微驱动器实测位移由11.5μm增大至13.9μm,这一结果与传统多晶硅材料弯曲梁式微驱动器的驱动位移5μm相比有显著提高,而能耗亦从180mW降至21.6mW,器件性能得到改善。     

Revisiting the Limiting Factors for Overall Water-Splitting on Organic Photocatalysts

In pursuit of inexpensive and earth abundant photocatalysts for solar hydrogen production from water, conjugated polymers have shown potential to be a viable alternative to widely used inorganic counterparts. The photocatalytic performance of polymeric photocatalysts, however, is very poor in comparison to that of inorganic photocatalysts. Most of the organic photocatalysts are active in hydrogen production only when a sacrificial electron donor (SED) is added into the solution, and their high performances often rely on presence of noble metal co-catalyst (e.g. Pt). For pursuing a carbon neutral and cost-effective green hydrogen production, unassisted hydrogen production solely from water is one of the critical requirements to translate a mere bench-top research interest into the real world applications. Although this is a generic problem for both inorganic and organic types of photocatalysts, organic photocatalysts are mostly investigated in the half-reaction, and have so far shown limited success in hydrogen production from overall water-splitting. To make progress, this article exclusively discusses critical factors that are limiting the overall water-splitting in organic photocatalysts. Additionally, we also have extended the discussion to issues related to stability, accurate reporting of the hydrogen production as well as challenges to be resolved to reach 10 % STH (solar-to-hydrogen) conversion efficiency.     

Revisiting the Limiting Factors for Overall Water‐Splitting on Organic Photocatalysts

In pursuit of inexpensive and earth abundant photocatalysts for solar hydrogen production from water, conjugated polymers have shown potential to be a viable alternative to widely used inorganic counterparts. The photocatalytic performance of polymeric photocatalysts, however, is very poor in comparison to that of inorganic photocatalysts. Most of the organic photocatalysts are active in hydrogen production only when a sacrificial electron donor (SED) is added into the solution, and their high performances often rely on presence of noble metal co‐catalyst (e.g. Pt). For pursuing a carbon neutral and cost‐effective green hydrogen production, unassisted hydrogen production solely from water is one of the critical requirements to translate a mere bench‐top research interest into the real world applications. Although this is a generic problem for both inorganic and organic types of photocatalysts, organic photocatalysts are mostly investigated in the half‐reaction, and have so far shown limited success in hydrogen production from overall water‐splitting. To make progress, this article exclusively discusses critical factors that are limiting the overall water‐splitting in organic photocatalysts. Additionally, we also have extended the discussion to issues related to stability, accurate reporting of the hydrogen production as well as challenges to be resolved to reach 10 % STH (solar‐to‐hydrogen) conversion efficiency.     

Factors influencing the electroreductive polymerization of di‐n‐hexyldichlorosilane

This paper reports the study of the effects of solvent, support electrolyte and the nature of the electrodes on the electroreduction of di‐n‐hexyldichlorosilane. The work performed involved the use of different types of sacrificial anode (magnesium, aluminium and zinc) and cathode (magnesium, aluminium, zinc, stainless steel, nickel, carbon and palladium) in tetrahydrofuran containing lithium perchlorate (LiClO₄). Monomodal poly(di‐n‐hexyldichlorosilane) was obtained with Al/Al and Mg/Mg electrode pairs, but the polymer yield was about ten times higher with Al/Al (11%) than with Mg/Mg (1%). From the solvents and co‐solvents used (tetrahydrofuran, hexamethylphosphorotriamide, acetone, hexane, toluene, 1,1,3,3‐tetramethylurea, tris(3,6‐dioxaheptyl)amine, 1,2‐dimethoxyethane, N,N‐dimethylacetamide and dimethylformamide) with LiClO₄, only the system tetrahydrofuran + hexamethylphosphorotriamide, tetrahydrofuran + N,N‐dimethylacetamide and tetrahydrofuran + toluene have given monomodal poly(di‐n‐hexyldichlorosilane) using an aluminium anode and stainless‐steel cathode. Copyright © 2001 John Wiley & Sons, Ltd.     

Electrocatalytic hydrogenation of organic compounds using current density gradient and sacrificial anode of nickel

Preparative electrocatalytic hydrogenation (ECH) of some organic compounds were performed: cyclohexene, 2-cyclohexen-1-one, benzaldehyde, acetophenone, styrene, 1,3-cyclohexadiene, trans-trans-2,4-hexadien-1-ol, citral, linalool and geraniol. H₂O/MeOH (1:1), NH₄OAc or NH₄Cl (0.2 M) were used as solvent and supporting electrolyte. A sacrificial anode of nickel allowed the use of an undivided cell, with a cell voltage varying between 2.3 and 1.3 V, depending on the supporting electrolyte. A current density gradient was applied to diminish the time of reaction and obtain a good electrochemical efficiency. An in situ prepared cathode of nickel deposited on iron provided a highly efficient ECH process, and the constant deposition of nickel on the electrode surface avoided catalyst poisoning. The ECH system was somewhat selective, hydrogenating conjugated olefins in good yield.     

混合稀土在铝基阳极中的作用

探讨了混合稀土金属对ＡｌＺｎＩｎＳｎＭｇ系阳极电化学性能和微观组织的影响，发现温度低于８０℃的工作环境下，混合稀土有使阳极工作电位正化的倾向，但可使阳极表面溶解均匀，避免电流效率降低，从而提高Ａｌ基阳极高温工作时的电化学保护性能。稀土金属能细化晶粒，抑制第二相对阳极晶界的导通腐蚀，是阳极性能提高的主要原因。     

异硫氰酸酯的还原偶联

本文以镁为消耗性电极(阳极), 进行了异硫氰酸酯的电极还原偶联反应的研究, 得到了双分子偶联产物-N, N'-二烃基二硫代草酸胺。     

异氰酸酯的反应≠

我们研究了芳基和烷基异氰酸酯在消耗性镁阳极存在下的有机电解反应。芳基异氰酸酯电解得N,N’-二取代脲,烷基异氰酸酯则还原偶联为N,N’-二取代草酰胺。我们认为这是由于烷基异氰酸酯从阴极得到电子发生双分子偶联,芳基异氰酸酯则是与阴极析出的高分散的活性镁起作用。