Microfluidic Pumping With Optically Induced Actuation of a Carbon Nanotube Membrane

2010 ◽  
Author(s):  
Joseph D. Duff ◽  
Stuart J. Williams ◽  
Balaji Panchapakesan
Keyword(s):  
Carbon Nanotubes ◽  
Low Cost ◽  
Fluid Motion ◽  
Pressure Head ◽  
Low Noise ◽  
Device Fabrication ◽  
Alternative Methods ◽  
Micro Pump ◽  
Photomechanical Actuation ◽  
Optically Induced

We present the design; fabrication and testing of a Polydimethylsiloxane (PDMS)-based microfluidic pump with optically induced membrane actuation. The thin membrane consists of a layer of PDMS (100 μm) and a layer of carbon nanotubes (190 nm). An applied infrared laser opto-mechanically activates the film of carbon nanotubes (CNT), leading to membrane deformation and subsequent fluid motion. Photomechanical actuation offers an alternative way to drive microfluidic devices and provides distinct advantages over alternative methods. The advantages include simplistic, low-cost device fabrication, Wireless actuation, remote controllability electrical–mechanical decoupling, low noise and the elimination of electrical circuits. The performance of this pump in terms of pressure head and flow rate is substantially high. In addition, the micro pump is self-priming and insensitive to particles and bubbles in the pumped media.

scholarly journals Low-cost formation of bulk and localized polymer-derived carbon nanodomains from polydimethylsiloxane

2015 ◽  
Vol 6 ◽  
pp. 744-748 ◽  
Author(s):  
Juan Carlos Castro Alcántara ◽  
Mariana Cerda Zorrilla ◽  
Lucia Cabriales ◽  
Luis Manuel León Rossano ◽  
Mathieu Hautefeuille
Keyword(s):  
Carbon Nanotubes ◽  
Laser Ablation ◽  
Low Cost ◽  
Chemical Vapour ◽  
Alternative Methods ◽  
Multi Wall Carbon Nanotubes ◽  
Custom Made ◽  
Direct Laser ◽  
Simple Alternative ◽  
Walled Carbon Nanotubes

We present two simple alternative methods to form polymer-derived carbon nanodomains in a controlled fashion and at low cost, using custom-made chemical vapour deposition and selective laser ablation with a commercial CD-DVD platform. Both processes presented shiny and dark residual materials after the polymer combustion and according to micro-Raman spectroscopy of the domains, graphitic nanocrystals and carbon nanotubes have successfully been produced by the combustion of polydimethylsiloxane layers. The fabrication processes and characterization of the byproduct materials are reported. We demonstrate that CVD led to bulk production of graphitic nanocrystals and single-walled carbon nanotubes while direct laser ablation may be employed for the formation of localized fluorescent nanodots. In the latter case, graphitic nanodomains and multi-wall carbon nanotubes are left inside microchannels and preliminary results seem to indicate that laser ablation could offer a tuning control of the nature and optical properties of the nanodomains that are left inside micropatterns with on-demand geometries. These low-cost methods look particularly promising for the formation of carbon nanoresidues with controlled properties and in applications where high integration is desired.

Transmission Electron Microscopy of oriented Co84Cr14Ta2 thin films for longitudinal magnetic recording

1991 ◽  
Vol 49 ◽  
pp. 756-757
Author(s):  
T. P. Nolan
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Cost ◽  
Low Noise ◽  
Information Storage ◽  
High Coercivity ◽  
Magnetic Alloy ◽  
Magnetic Media ◽  
Transmission Electron

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.

Carbon Nanotube Gas Sensor Fabricated on Anodic Aluminum Oxide

2007 ◽  
Vol 124-126 ◽  
pp. 1309-1312
Author(s):  
Nguyen Duc Hoa ◽  
Nguyen Van Quy ◽  
Gyu Seok Choi ◽  
You Suk Cho ◽  
Se Young Jeong ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Gas Sensor ◽  
Chemical Vapor ◽  
Fast Response ◽  
Device Fabrication ◽  
Alumina Oxide ◽  
Response And Recovery ◽  
New Type ◽  
P Type

A new type of gas sensor was realized by directly depositing carbon nanotube on nano channels of the anodic alumina oxide (AAO) fabricated on p-type silicon substrate. The carbon nanotubes were synthesized by thermal chemical vapor deposition at a very high temperature of 1200 oC to improve the crystallinity. The device fabrication process was also developed. The contact of carbon nanotubes and p-type Si substrate showed a Schottky behavior, and the Schottky barrier height increased with exposure to gases while the overall conductivity decreased. The sensors showed fast response and recovery to ammonia gas upon the filling (400 mTorr) and evacuation.

Electrostatic bellow muscle actuators and energy harvesters that stack up

2021 ◽  
Vol 6 (51) ◽  
pp. eaaz5796
Author(s):  
I. D. Sîrbu ◽  
G. Moretti ◽  
G. Bortolotti ◽  
M. Bolignari ◽  
S. Diré ◽  
...  
Keyword(s):  
High Performance ◽  
High Reliability ◽  
Low Cost ◽  
Artificial Muscle ◽  
Pressure Head ◽  
Robotic Systems ◽  
Maximum Pressure ◽  
Term Operation ◽  
Energy Harvesters ◽  
Out Of Plane

Future robotic systems will be pervasive technologies operating autonomously in unknown spaces that are shared with humans. Such complex interactions make it compulsory for them to be lightweight, soft, and efficient in a way to guarantee safety, robustness, and long-term operation. Such a set of qualities can be achieved using soft multipurpose systems that combine, integrate, and commute between conventional electromechanical and fluidic drives, as well as harvest energy during inactive actuation phases for increased energy efficiency. Here, we present an electrostatic actuator made of thin films and liquid dielectrics combined with rigid polymeric stiffening elements to form a circular electrostatic bellow muscle (EBM) unit capable of out-of-plane contraction. These units are easy to manufacture and can be arranged in arrays and stacks, which can be used as a contractile artificial muscle, as a pump for fluid-driven soft robots, or as an energy harvester. As an artificial muscle, EBMs of 20 to 40 millimeters in diameter can exert forces of up to 6 newtons, lift loads over a hundred times their own weight, and reach contractions of over 40% with strain rates over 1200% per second, with a bandwidth over 10 hertz. As a pump driver, these EBMs produce flow rates of up to 0.63 liters per minute and maximum pressure head of 6 kilopascals, whereas as generator, they reach a conversion efficiency close to 20%. The compact shape, low cost, simple assembling procedure, high reliability, and large contractions make the EBM a promising technology for high-performance robotic systems.

Application of nanomaterials in microbial-cell biosensor constructions

2015 ◽  
Vol 69 (1) ◽  
Author(s):  
Jana Šefčovičová ◽  
Jan Tkac
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Rapid Detection ◽  
Food Industry ◽  
Low Cost ◽  
Microbial Cell ◽  
Direct Connection ◽  
Qualitative Detection ◽  
Analytical Tools ◽  
Cell Biosensor

AbstractMicrobial cell biosensors, where cells are in direct connection with a transducer enabling quantitative and qualitative detection of an analyte, are very promising analytical tools applied mainly for assays in the environmental field, food industry or biomedicine. Microbial cell biosensors are an excellent alternative to conventional analytical methods due to their specificity, rapid detection and low cost of analysis. Nowadays, nanomaterials are often used in the construction of biosensors to improve their sensitivity and stability. In this review, the combination of microbial and other individual cells with different nanomaterials (carbon nanotubes, graphene, gold nanoparticles, etc.) for the construction of biosensors is described and their applications are provided as well.

scholarly journals Metal-Assisted Chemical Etching for Anisotropic Deep Trenching of GaN Array

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3179
Author(s):  
Qi Wang ◽  
Kehong Zhou ◽  
Shuai Zhao ◽  
Wen Yang ◽  
Hongsheng Zhang ◽  
...  
Keyword(s):  
Chemical Etching ◽  
Low Cost ◽  
Etching Rate ◽  
Surface Damage ◽  
Device Fabrication ◽  
Irreversible Damage ◽  
Catalytic Role ◽  
Metal Assisted Chemical Etching ◽  
Gan Etching

Realizing the anisotropic deep trenching of GaN without surface damage is essential for the fabrication of GaN-based devices. However, traditional dry etching technologies introduce irreversible damage to GaN and degrade the performance of the device. In this paper, we demonstrate a damage-free, rapid metal-assisted chemical etching (MacEtch) method and perform an anisotropic, deep trenching of a GaN array. Regular GaN microarrays are fabricated based on the proposed method, in which CuSO4 and HF are adopted as etchants while ultraviolet light and Ni/Ag mask are applied to catalyze the etching process of GaN, reaching an etching rate of 100 nm/min. We comprehensively explore the etching mechanism by adopting three different patterns, comparing a Ni/Ag mask with a SiN mask, and adjusting the etchant proportion. Under the catalytic role of Ni/Ag, the GaN etching rate nearby the metal mask is much faster than that of other parts, which contributes to the formation of deep trenches. Furthermore, an optimized etchant is studied to restrain the disorder accumulation of excessive Cu particles and guarantee a continuous etching result. Notably, our work presents a novel low-cost MacEtch method to achieve GaN deep etching at room temperature, which may promote the evolution of GaN-based device fabrication.

scholarly journals Nanocone-Shaped Carbon Nanotubes Field-Emitter Array Fabricated by Laser Ablation

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3244
Author(s):  
Jiuzhou Zhao ◽  
Zhenjun Li ◽  
Matthew Thomas Cole ◽  
Aiwei Wang ◽  
Xiangdong Guo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Laser Ablation ◽  
High Performance ◽  
Low Cost ◽  
Field Emitter ◽  
Beam Focusing ◽  
Field Emitter Arrays ◽  
Emitter Array ◽  
Field Emitter Array ◽  
Tip Radius

The nanocone-shaped carbon nanotubes field-emitter array (NCNA) is a near-ideal field-emitter array that combines the advantages of geometry and material. In contrast to previous methods of field-emitter array, laser ablation is a low-cost and clean method that does not require any photolithography or wet chemistry. However, nanocone shapes are hard to achieve through laser ablation due to the micrometer-scale focusing spot. Here, we develop an ultraviolet (UV) laser beam patterning technique that is capable of reliably realizing NCNA with a cone-tip radius of ≈300 nm, utilizing optimized beam focusing and unique carbon nanotube–light interaction properties. The patterned array provided smaller turn-on fields (reduced from 2.6 to 1.6 V/μm) in emitters and supported a higher (increased from 10 to 140 mA/cm2) and more stable emission than their unpatterned counterparts. The present technique may be widely applied in the fabrication of high-performance CNTs field-emitter arrays.

Large scale and low cost synthesis of multiwalled carbon nanotubes by mechanothermal absence catalysts

2010 ◽  
Vol 109 (1) ◽  
pp. 25-30 ◽  
Author(s):  
S A Manafi ◽  
M H Amin ◽  
M R Rahimipour ◽  
E Salahi ◽  
A Kazemzadeh
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Large Scale ◽  
Low Cost ◽  
Multiwalled Carbon
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