Micro and Nano Systems Letters最新文献

{"title":"Green synthesized plant-based silver nanoparticles: therapeutic prospective for anticancer and antiviral activity","authors":"Nancy Jain,&nbsp;Priyanshu Jain,&nbsp;Devyani Rajput,&nbsp;Umesh Kumar Patil","doi":"10.1186/s40486-021-00131-6","DOIUrl":"https://doi.org/10.1186/s40486-021-00131-6","url":null,"abstract":"<p>Nanotechnology holds an emerging domain of medical science as it can be utilized virtually in all areas. Phyto-constituents are valuable and encouraging candidates for synthesizing green silver nanoparticles (AgNPs) which possess great potentials toward chronic diseases. This review gives an overview of the Green approach of AgNPs synthesis and its characterization. The present review further explores the potentials of Phyto-based AgNPs toward anticancer and antiviral activity including its probable mechanism of action. Green synthesized AgNPs prepared by numerous medicinal plants extract are critically reviewed for cancer and viral infection. Thus, this article mainly highlights green synthesized Phyto-based AgNPs with their potential applications for cancer and viral infection including mechanism of action and therapeutic future prospective in a single window. </p>","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"9 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2021-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40486-021-00131-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4479604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High speed silicon wet anisotropic etching for applications in bulk micromachining: a review","authors":"Prem Pal,&nbsp;Veerla Swarnalatha,&nbsp;Avvaru Venkata Narasimha Rao,&nbsp;Ashok Kumar Pandey,&nbsp;Hiroshi Tanaka,&nbsp;Kazuo Sato","doi":"10.1186/s40486-021-00129-0","DOIUrl":"https://doi.org/10.1186/s40486-021-00129-0","url":null,"abstract":"<p>Wet anisotropic etching is extensively employed in silicon bulk micromachining to fabricate microstructures for various applications in the field of microelectromechanical systems (MEMS). In addition, it is most widely used for surface texturing to minimize the reflectance of light to improve the efficiency of crystalline silicon solar cells. In wet bulk micromachining, the etch rate is a major factor that affects the throughput. Slower etch rate increases the fabrication time and therefore is of great concern in MEMS industry where wet anisotropic etching is employed to perform the silicon bulk micromachining, especially to fabricate deep cavities and freestanding microstructures by removal of underneath material through undercutting process. Several methods have been proposed to increase the etch rate of silicon in wet anisotropic etchants either by physical means (e.g. agitation, microwave irradiation) or chemically by incorporation of additives. The ultrasonic agitation during etching and microwave irradiation on the etchants increase the etch rate. However, ultrasonic method may rupture the fragile structures and microwave irradiation causes irradiation damage to the structures. Another method is to increase the etching temperature towards the boiling point of the etchant. The etching characteristics of pure potassium hydroxide solution (KOH) is studied near the boiling point of KOH, while surfactant added tetramethylammonium hydroxide (TMAH) is investigated at higher temperature to increase the etch rate. Both these studies have shown a potential way of increasing the etch rate by elevating the temperature of the etchants to its boiling point, which is a function of concentration of etch solution. The effect of various kinds of additives on the etch rate of silicon is investigated in TMAH and KOH. In this paper, the additives which improve the etch rate have been discussed. Recently the effect of hydroxylamine (NH₂OH) on the etching characteristics of TMAH and KOH is investigated in detail. The concentration of NH₂OH in TMAH/KOH is varied to optimize the etchant composition to obtain improved etching characteristics especially the etch rate and undercutting which are important parameters for increasing throughput. In this article, different methods explored to improve the etch rate of silicon have been discussed so that the researchers/scientists/engineers can get the details of these methods in a single reference.</p>","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"9 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2021-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5155008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-step electropolymerization of methylene blue films on highly flexible carbon fiber electrode as supercapacitors","authors":"Leandro Marques Samyn,&nbsp;Rajendran Suresh Babu,&nbsp;Mani Devendiran,&nbsp;Ana Lucia Ferreira de Barros","doi":"10.1186/s40486-021-00130-7","DOIUrl":"https://doi.org/10.1186/s40486-021-00130-7","url":null,"abstract":"<p>Energy crisis and environmental pollution have been one of the major global issues. In this regard, the search for new energy storage materials is cheap, flexible and high-performance supercapacitors electrode which has become intensive. Also, reducing the amount of organic dyes polluting in water is a great significance. Herein, one-step electropolymerization of methylene blue on carbon fiber and the resulting films were applied to the supercapacitor. The high performance is associated to the outstanding conductivity, electrochemical stability and superior mechanical flexibility of carbon fiber. A new flexible electrode for supercapacitors was successfully fabricated by demonstrating with a good electrochemical performance and a promising alternative to reduce the water pollution.</p>","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"9 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2021-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40486-021-00130-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4853791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on thickness-dependence characteristics of bismuth ferrite (BFO) for ultraviolet (UV) photodetector application","authors":"Shahnaz Kossar,&nbsp;R. Amiruddin,&nbsp;Asif Rasool","doi":"10.1186/s40486-020-00128-7","DOIUrl":"https://doi.org/10.1186/s40486-020-00128-7","url":null,"abstract":"<p>The present research work reports on the fabrication of ultraviolet (UV) photodetectors using bismuth ferrite (BiFeO_3, BFO) thin films with varying thickness. Using the spray pyrolysis technique, BFO thin films were deposited on the glass substrate at 673?K. The deposited BFO thin films were characterized by Raman and FTIR spectroscopic analysis. The morphological analysis reveals uniform grain distribution for the prepared BFO samples. The optical analysis reveals that transmittance value decreases upon an increase in the thickness of BFO thin films and the calculated optical band gap value lies between 2.0 to 2.3?eV. The varying thickness of the BFO active layer was stacked between ITO and Al electrodes and the current–voltage (I–V) characteristics of the fabricated ITO/BFO/Al devices were studied under dark and UV illumination (λ?=?365?nm). It was observed that BFO with an optimum thickness (365?nm) exhibits higher photoresponsivity of 110?mA/W with an external quantum efficiency (EQE) of 37.30%. The impact of different thickness of the BFO active layer, the role of adsorption and desorption of oxygen (O₂) molecules upon the surface of BFO layers towards UV photoresponse characteristics were investigated.</p>","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"9 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2021-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40486-020-00128-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4501805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"All-soft multiaxial force sensor based on liquid metal for electronic skin","authors":"Kyuyoung Kim,&nbsp;Junseong Ahn,&nbsp;Yongrok Jeong,&nbsp;Jungrak Choi,&nbsp;Osman Gul,&nbsp;Inkyu Park","doi":"10.1186/s40486-020-00126-9","DOIUrl":"https://doi.org/10.1186/s40486-020-00126-9","url":null,"abstract":"<p>Electronic skin (E-skin) capable of detecting various physical stimuli is required for monitoring external environments accurately. Here, we report an all-soft multiaxial force sensor based on liquid metal microchannel array for electronic skin applications. The proposed sensor is composed of stretchable elastomer and Galinstan, a eutectic gallium-indium alloy, providing a high mechanical flexibility and electro-mechanical durability. Liquid metal microchannel arrays are fabricated in multilayer and positioned along a dome structure to detect multi-directional forces, supported by numerical simulation results. By adjusting the height of the dome, we could control the response of the multiaxial sensor with respect to the deflection. As a demonstration of multiaxial force sensing, we were able to monitor the direction of multidirectional forces using a finger by the response of liquid metal microchannel arrays. This research could be applied to various fields including soft robotics, wearable devices, and smart prosthetics for artificial intelligent skin applications.</p>","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"9 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2021-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40486-020-00126-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4163145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hollow polydimethylsiloxane (PDMS) foam with a 3D interconnected network for highly sensitive capacitive pressure sensors","authors":"Dong Hwan Kim,&nbsp;Young Jung,&nbsp;Kyungkuk Jung,&nbsp;Dong Hwa Kwak,&nbsp;Dong Min Park,&nbsp;Myung Gyu Shin,&nbsp;Hyeong Jun Tak,&nbsp;Jong Soo Ko","doi":"10.1186/s40486-020-00127-8","DOIUrl":"https://doi.org/10.1186/s40486-020-00127-8","url":null,"abstract":"<p>We propose a highly sensitive capacitive pressure sensor made of hollow polydimethylsiloxane (PDMS) foam with a three-dimensional network structure. The stiffness of the foam is adjusted by the viscosity of the PDMS solution. The fabricated PDMS-30 (PDMS 30 wt%) foam shows extremely high porosity (&gt;?86%) approximately 19 times that of bare PDMS (PDMS 100 wt%) foam. Capacitive pressure sensors fabricated using the foam possess high sensitivity, good compressibility (up to 80% strain), and consistent output characteristics in a 2000-cycle test.</p>","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"8 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2020-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40486-020-00127-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4568222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to: Microfluidic resonators with two parallel channels for independent sample loading and effective density tuning","authors":"Jungchul Lee,&nbsp;Faheem Khan,&nbsp;Thomas Thundat,&nbsp;Bong Jae Lee","doi":"10.1186/s40486-020-00125-w","DOIUrl":"https://doi.org/10.1186/s40486-020-00125-w","url":null,"abstract":"","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"8 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40486-020-00125-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4802073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rayleigh–Bénard instability in nanofluids: a comprehensive review","authors":"Jyoti Ahuja,&nbsp;Jyoti Sharma","doi":"10.1186/s40486-020-00123-y","DOIUrl":"https://doi.org/10.1186/s40486-020-00123-y","url":null,"abstract":"<p>The extraordinary enhancement in heat transfer efficiency of nanofluids at extremely low volume fractions has attracted a lot of attention in identifying the governing mechanisms. The nanoscale effects, Brownian motion (random motion of particles inside the base fluid) and thermophoresis (diffusion of particles due to temperature gradient) are found to be important slip mechanisms in nanofluids. Based on these findings, a set of partial differential equations for conservation laws for nanofluids was formed. Since then, a large number of mathematical studies on convective heat transfer in nanofluids became feasible. The present paper summarizes the studies pertaining to instability of a horizontal nanofluid layer under the impact of various parameters such as rotation, magnetic field, Hall currents and LTNE effects in both porous and non-porous medium. Initially, investigations were made using the model considering fixed initial and boundary conditions on the layer, gradually the model was revised in the light of more practical boundary conditions and recently it has been modified to get new and more interesting results. The exhaustive analysis of instability problems is presented in the paper and prospects for future research are also identified.</p>","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"8 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40486-020-00123-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4555282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and performance evaluation of thin-film actuators based on flexible Ni-Co substrates","authors":"Suhwan Kim,&nbsp;Woojin Kim,&nbsp;Yongdae Kim","doi":"10.1186/s40486-020-00122-z","DOIUrl":"https://doi.org/10.1186/s40486-020-00122-z","url":null,"abstract":"<p>This paper proposes a new design of bimorph-type electrothermal actuators based on flexible Ni-Co substrates and describes the results of the finite element method (FEM) simulation and performance evaluation of the actuators. In the design of the actuators, a multilayer structure consisting of an adhesion layer, two insulation layers, and a Pt (platinum) heater layer was formed on the Ni-Co flexible substrate that was patterned in an individual shape. The thin-film actuators proposed in this study could be detached from a Si carrier wafer and adhered to other micro or macrostructural elements. To investigate the temperature distribution and mechanical behavior of the actuators, multiphysics FEM simulations combining electrothermal and static structural analyses were carried out. The actuators were fabricated using conventional microfabrication and electroplating technologies on Si carrier wafer; then, the actuators were peeled off from the carrier wafer using the release process proposed in this paper. After fabricating the actuators, the deflection of their tips was evaluated and compared with that obtained from the FEM simulations.</p>","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"8 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40486-020-00122-z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4553369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Planar free-standing metal layer fabrication: implementing sub-structures in micromirror arrays for light steering applications","authors":"Natalie Worapattrakul,&nbsp;Andreas Tatzel,&nbsp;Volker Viereck,&nbsp;Hartmut Hillmer","doi":"10.1186/s40486-020-00124-x","DOIUrl":"https://doi.org/10.1186/s40486-020-00124-x","url":null,"abstract":"<p>We present a method to fabricate planar metal layers to be used as micromachined mirrors. Released mirrors of pure metal involve severe stress and reveal specific challenges to obtain planar mirror structures. Introducing sub-structures generating corrugated patterns, the metal mirror layers can be mechanically stabilized and undesired mirror bending can be reduced. For our investigations we used different arrangements of line structures on our metal mirrors, such as a group of straight or curved lines oriented differently. Comparing all the implemented different designs, planar micromirrors were achieved via sub-structures with a combination of straight lines arranged orthogonally to a single line. These planar micromirrors allow steering of the incident light by reflection and adjustment of the window transmittance. The presented low-cost method is suitable for large area fabrication of micromirror arrays, but also can be customized for other applications, where planar free-standing metal layers are required.</p>","PeriodicalId":704,"journal":{"name":"Micro and Nano Systems Letters","volume":"8 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4399636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}