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The Young's moduli of carbon nanotubes and carbon nanotube thin films (the so called buckypaper) are investigated using nanoscale mechanics and Molecular Dynamic (MD) simulation methods. The results show that the Young's modulus of single walled (10, 10) carbon nanotubes ranges from 0.75 TPa to 0.9 TPa, which agrees well with some published data in the literature. For single layer buckypapers of single-walled...
We developed reaction chamber arrays with a volume of a few femtoliters to monitor biological reactions at single-molecule level. Micro-meter holes were fabricated on the surface of a silicone elastic sheet (PDMS). Sample solutions were sandwiched between the fabricated sheet and a glass surface. Resultantly, solutions were enclosed in each chamber hermetically. The uniformly shaped chambers allow...
This paper presents a new 2D structure to measure a chemotactic migration of adhesive cells for analysis of cell kinetics. This structure was designed to overcome Boyden chamber's disadvantages and made real-time measurement possible in 2D. The 2D chip was made of PDMS and glass for transparency. To create more than 2% of concentration gradient for chemotaxis measurement, the PDMS chip has a gradually...
After 45 years of unfortunate delay, nanodiamond particles having 4.8±0.7 nm in diameter are now emerging as one of the most promising candidates for a general purpose material in nanotechnology for the reasons of (1) low cost, (2) non-toxicity, (3) high crystallinity, and (4) versatile maneuverability. (1) The raw material is a TNT-based war explosive, once most popular, over-produced but now becoming...
A novel microfluidic platform is presented for sorting by size dissociated neurons, glia and stem cells from biopsies of the central nerve system. A highly biocompatible aqueous polymer solution was used in hydrodynamic spreading controlled cell separation. Before cell separation, particles were used for demonstration. To verify the results the fractions were studied using flow cytometry. Further,...
Based on previous experimental results of the Carbon Nanotubes-based (CNTs-based) micro bubble generation in static water presented by our group, the dynamic characteristic of CNTs-based micro bubble will be introduced in this paper. The movement of CNTs-based micro bubble is categorized into two forms: micro bubble transportation in the micro channel driven by aqueous flow induced by the micro pump...
Polydimethylsiloxane (PDMS) microfluidic chips with various cross-junction angles were designed and fabricated by MEMS and soft lithography technologies to construct chitosan microfibers. Chitosan solution and sodium tripolyphosphate (STPP) solution were injected into the cross-junction microchannel of the microfluidic chip, which generated the laminar flow of chitosan solution by the hydrodynamic...
This paper addresses several challenges in the formation of an Au cantilever taking Cu as a sacrificial layer. With respect to the Cu wet etch process, an etchant containing HAC and H2O2 works most effectively in anchor corrosion process and an etchant involving FeCl2 and HCl achieves better performance in the Cu sacrificial layer release process. Moreover, we probe into the wrinkle phenomenon of...
This work presents the design, fabrication and experiments of a new blood-filtering chip based on SU-8 and PDMS. The main function of this blood-filtering chip is to filter the leukocyte out of the blood. This new leukocyte filtered chip is composed of three parts: cover plate, filtering plate and receiving plate. The shape of the transfusing channel is optimized by simulation. The new blood-filtering...
The process parameters that influence the performance of nano-size hydroxyapatite powder such as purity, granularity, and crystallinity include the mass ratio between Ca(NO3)2middot4H2O and (NH4)2HPO4, the PH value of reaction liquid, the temperature of sintering and the time of heat preservation. Orthogonal experiments with different process parameters are designed; experiments were carried out with...
Fluid dynamics and mixing transport of the rhombic micromixer with truncate angles have been investigated by 3D numerical simulations and experiments. Simulation result shows this rhombic microchannel with truncate angles has high mixing efficiency, compared to cross-shape microchannel. Over 90% mixing enhanced by vortices had been achieved at Re > 100. Different to photolithography process, CO...
In this article, the 3D dynamic analysis was used to investigate the geometrical effect on the net flow rate of the novel microvalves in comparison with the conventional nozzle/diffuser microvalves. The novel microvalves with saw-tooth structures had been investigated by 3D transient simulations in order to study the transient flow behavior at different angles. Simulation parameters are half angle...
Most MEMS/NEMS devices are working on the harsh environment, such as high shock and temperature environment, ranging from aerospace science, automobile industry, mechanical engineering, to medical and safety engineering. The reliability of MEMS/NEMS devices is the most important issue today. MEMS devices must perform their required functions for the duration of the equipment's requirement profile...
This paper deduces a remarkably precise analytical formula for calculating the fundamental resonant frequency of V-shaped cantilevers using Rayleigh-Ritz method. This analytical formula, which is very convenient for MEMS sensor design, is then validated by ANSYS simulation. This formula raises a new perspective that, among all the V-shaped cantilevers, the simplest triangular cantilever can lead to...
It is reported that the most urgent issue for 90% of the blind is the sense of direction. Even today the blind is lack of electronic products to provide direction guide, a novel electrical blind stick system is designed in this paper, By listening to the alarm from the blind stick, the blind can judge whether they are walking on the blind road or not. This paper described the principle of the system...
A battery-powered miniaturized electroporation (EP) system was designed and fabricated to tackle the challenging DNA transfection of stem cells. The system consists of a programmable mini-electroporator and a micro EP chip. Large statistical data of loading efficiency for five different size molecules and cell viability were determined under various voltage and duration in this system for HeLa cell...
A micro-beam of a creative smart resonating gas sensor with a self-actuating and detecting (SAD) system is presented. The smart SAD sensor, in which the resonance frequency shifting of the MEMS cantilever is monitored to probe its mass change caused by adsorption of certain gas molecules, has never need exclusive detection circuits and instruments, and the micro-beam has never need additional detective...
The aim of the study is to evaluate the cell affinity of poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) thin films using a parallel plate flow chamber system. The PHBV thin films were modified by anhydrous ammonia gaseous plasma treatment. Mouse 3T3 fibroblast cells were seeded on bare and plasma modified PHBV thin films, respectively. A laminar flow enforces the cells on these films...
This paper reports a previously overlooked mechanism that has a considerable effect to undermine bubble-driven micropumping in a square-shaped microchannel, and therefore limits the maximum achievable pressure head. Improvement of pumping performance by rounding the microchannel is thus proposed.
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