Electroosmotic Pumps Fabricated From Porous Silicon Membranes

2004 ◽  
Author(s):  
Shuhuai Yao ◽  
Alan M. Myers ◽  
Jonathan D. Posner ◽  
Juan G. Santiago
Keyword(s):  
Porous Silicon ◽  
Flow Rate ◽  
Maximum Flow ◽  
Applied Potential ◽  
Flow Rates ◽  
Pump Performance ◽  
Silicon Membranes ◽  
Electroosmotic Pumps ◽  
The Impact ◽  
Large Flow

Large flow rates per applied potential are obtained from electroosmotic (EO) pumps fabricated from n-type porous silicon. Porous silicon membranes have ideal geometries for EO pumping. These membranes have hexagonally packed, uniform pores with near-unity tortuosity and are well suited to maximize flow rate for a given applied voltage. The 350 μm thick membranes were passivated with a SiO2 layer and exhibit a maximum flow rate of 1.2 ml/min/cm2/V. This is 4.4 times higher than previously demonstrated silica-based frit EO pumps. LPCVD polysilicon deposition followed by wet oxidation was used to control the pore size. The impact of these coatings on the pump performance has also been characterized.

Optimization of Inlet Ring Groove Arrangement for Suppression of Unstable Flow in a Centrifugal Impeller

2005 ◽  
Author(s):  
Masahiro Ishida ◽  
Daisaku Sakaguchi ◽  
Hironobu Ueki
Keyword(s):  
Flow Rate ◽  
The Other ◽  
Centrifugal Impeller ◽  
Shape Parameters ◽  
Unstable Flow ◽  
Ring Groove ◽  
Flow Rates ◽  
Small Flow ◽  
Specific Speed ◽  
Large Flow

An optimization of the inlet ring groove arrangement has been pursued in the present study for obtaining better impeller characteristics and a wider operation range at both small and large flow rates in a high specific speed type centrifugal impeller with inducer. The effects of the shape parameters with respect to the inlet ring groove on the impeller characteristic and the flow incidence were analyzed mainly based on numerical simulations, but also compared to the experimental results. At small flow rates, a significant improvement in the impeller characteristic is achieved due to reduction in the excessive-positive flow incidence by optimizing both location and width of the rear groove near the inducer tip throat. On the other hand, the impeller characteristic is improved at large flow rates by implementing the corner radius at the rear groove edge and by placing another front ring groove in the suction pipe. As a result, by the optimized configuration of the front and rear ring grooves, the unstable flow range of the test impeller can be reduced by about 50% without deterioration of the impeller characteristic even at the 125% flow rate.

Thermodynamic Efficiency of Porous Glass Electroosmotic Pumps

2003 ◽  
Author(s):  
Shuhuai Yao ◽  
Shulin Zeng ◽  
Juan G. Santiago
Keyword(s):  
Zeta Potential ◽  
Flow Rate ◽  
Maximum Flow ◽  
Pump Current ◽  
Thermodynamic Efficiency ◽  
Two Phase ◽  
Poisson Boltzmann ◽  
Electroosmotic Pumps ◽  
Poisson Boltzmann Equation ◽  
Pump Pressure

This paper presents an analytical and experimental study of electroosmotic (EO) pumps designed to be integrated with two-phase microchannel heat exchangers with load capacities of order 100 W and greater. We have fabricated sintered glass EO pumps that provide maximum flow rates and pressure capacities 33 ml/min and 1.3 atm, respectively, at 100 V applied potentials. We have developed an analytical model to solve for electroosmotic flow rate, total pump current, and thermodynamic efficiency as a function of pump pressure load for these porous-structure EO pumps. The model uses a symmetric electrolyte approximation valid for the high zeta potential regime and numerically solves the Poisson-Boltzmann equation for charge distribution in the idealized pore geometry. The model also incorporates an approximate ionic-strength-dependent zeta potential formulation. The effects of pressure and flow rate on thermodynamic efficiency are also analyzed theoretically and compared to our measurements.

scholarly journals Study on the Formation Law of the Freezing Temperature Field of Freezing Shaft Sinking under the Action of Large-Flow-Rate Groundwater

2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Bin Wang ◽  
Chuan-xin Rong ◽  
Jian Lin ◽  
Hua Cheng ◽  
Hai-bing Cai
Keyword(s):  
Temperature Field ◽  
Groundwater Flow ◽  
Flow Velocity ◽  
Flow Rate ◽  
Freezing Temperature ◽  
Freezing Process ◽  
Flow Rates ◽  
Porosity Reduction ◽  
Shaft Sinking ◽  
Large Flow

Taking into account moisture migration and heat change during the soil freezing process, as well as the influence of absolute porosity reduction on seepage during the freezing process, we construct a numerical model of hydrothermal coupling using laws of conservation of energy and mass. The model is verified by the results of large-scale laboratory tests. By applying the numerical calculation model to the formation of artificial shaft freezing temperature fields under the action of large-flow groundwater, we conclude that groundwater with flow rates of less than 5 m/d will not have a significant impact on the artificial freezing temperature field. The maximum flow rates that can be handled by single-row freezing pipes and double-row freezing pipes are 10 m/d and 20 m/d, respectively, during the process of freezing shaft sinking. By analyzing the variation of groundwater flow rate during freezing process, we find that the groundwater flow velocity can reach 5–7 times the initial flow velocity near the closure moment of the frozen wall. Finally, in light of the action characteristics of groundwater on the freezing temperature field, we make suggestions for optimal pipe and row spacing in freezing pipe arrangement.

Temporal Response of Porous Glass Electroosmotic Pumps

2002 ◽  
Author(s):  
Shuhuai Yao ◽  
Shulin Zeng ◽  
Juan G. Santiago
Keyword(s):  
Flow Rate ◽  
Maximum Flow ◽  
Ion Concentration ◽  
Temporal Response ◽  
Short Term ◽  
Cooling Systems ◽  
Sintered Glass ◽  
Rate Capacity ◽  
Bioanalytical Applications ◽  
Electroosmotic Pumps

Sintered glass electroosmotic pumps have been fabricated that provide maximum flow rates and pressure capacities exceeding 14 ml/min and 1.4 atm, respectively, at 150 V, with an active pumping volume of less than 2 cm3. These compact devices with no moving parts have the potential to impact a variety of applications including microelectronics cooling systems and bioanalytical applications. We present here a preliminary a study of the response of the pumps to changes in fluidic load, including their short-term transient performance. A 0.5 mM borate buffer (pH = 9.2) is used to stabilize pump performance, with nearly optimal flow rate capacity. The experiments are conducted for working electrolytes of varying ion concentration. These performance characteristics are critical to applications that aim to use feedback control of flow rate and pressure over varying conditions.

Development of Robust Microvavles for Compact Robust Pumps/Hydraulic Actuators

2007 ◽  
Vol 121-123 ◽  
pp. 1207-1210
Author(s):  
B. Li ◽  
Q. Chen
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Pressure Support ◽  
Test Results ◽  
Valve Design ◽  
Standard Process ◽  
Flow Rates ◽  
Forward Flow ◽  
Large Flow

In situ UV-LIGA assembled robust micro check valves with large flow rates (>10 ml/s, displacement related), high-pressure support ability (>10 MPa) and high operational frequencies (>10 kHz) made of nano-structured nickel were presented in this paper. The microvalve consists of an array of 80 single micro valves to achieve the required flow rates. Test results show that the forward flow rate is about 19 ml/s under pressure of 90Psi. The backward flow rate is negligible. The reliability of the valve is ensured by the valve design and nanostructured nickel realized. The tested tensile strength of a nano structured nickel is about 1GPa. The strength of SU-8 is 50MPa, which is more than 50% higher that fabricated with a standard process.

scholarly journals Finite Element Simulation of Newtonian and Non-Newtonian Fluid through the Parallel Plates Affixed with Single Screen

2020 ◽  
Vol 13 (1) ◽  
pp. 69-83
Author(s):  
Abid Ali Memon ◽  
Muhammad Asif Memon ◽  
Kaleemullah Bhatti ◽  
Gul Muhammad Shaikh
Keyword(s):  
Reynolds Number ◽  
Finite Element ◽  
Newtonian Fluid ◽  
Flow Rate ◽  
Rectangular Channel ◽  
Maximum Flow ◽  
Least Square ◽  
Maximum Flow Rate ◽  
Parallel Plates ◽  
The Impact

In the contemporary research article we have performed a numerical investigation of the non-Newtonian fluid flow through a rectangular channel with a fixed solid screen devoted at the angles 100 to 450 degrees. We have employed the power-law model for shear thickening and shear thinning fluids with the high Reynolds number between 1000 and 10,000. The obstacle has been solved by putting in the Galerkin’s least square strategy of the finite element method and the procedure has been carried out utilizing the commercial software COMSOL Multiphysics. Various flow properties such as 'maximum flow rate' and 'pressure' have been discussed in the terms of the Reynolds number and also using the linear and quadratic regressions in order to establish the relationship between them for the future analysis. Moreover the impact of turning screen in the shape of increment in the maximum flow rate and pressure is checked in terms of Reynolds number and  Satisfactory results are gained in comparison with the results available in the literature.

Optimization of an Innovative Rotary Shaft Pump (RSP)

2006 ◽  
Vol 128 (6) ◽  
pp. 1281-1288 ◽  
Author(s):  
Jacob C. Allen ◽  
Phillip M. Ligrani
Keyword(s):  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Maximum Flow ◽  
Performance Data ◽  
Outer Diameter ◽  
Hydraulic Efficiency ◽  
Rotary Pump ◽  
Optimal Arrangement ◽  
Pump Performance ◽  
Pump Head

This paper describes the optimization of rotary shaft pump performance, which is accomplished by comparing the performance of four different centrifugal rotary pump configurations: hooked blades pump, backward-curved blades ID=12.7mm pump, contoured base pump, and backward-curved blades ID=19.1mm pump. Each of these devices utilizes a unique and simple impeller design where the blades are directly integrated into a shaft with an outer diameter of 25.4mm. Presented for each pump are performance data including volumetric flow rate, pump head, and hydraulic efficiency. When pumping water, the most optimal arrangement with the hooked impeller blades produces a maximum flow rate of 3.22L∕min and a pump head as high as 0.97m.

Effect of Formula Type and Preparation on International Dysphagia Diet Standardisation Initiative Thickness Level and Milk Flow Rates From Bottle Teats

2021 ◽  
Vol 30 (1) ◽  
pp. 260-265
Author(s):  
Britt F. Pados ◽  
Victoria Feaster
Keyword(s):  
Gastroesophageal Reflux ◽  
Infant Formula ◽  
Flow Rate ◽  
Infant Formulas ◽  
Testing Methods ◽  
Flow Rates ◽  
Milk Flow ◽  
Thin Liquids ◽  
The Impact ◽  
Formula Type

Purpose The purpose of this study was to evaluate the effect of infant formula type and preparation (i.e., ready-to-feed vs. powder) on International Dysphagia Diet Standardisation Initiative (IDDSI) thickness level and milk flow rates from bottle teats/nipples. Method The ready-to-feed and powder formulations of the following products were tested for IDDSI thickness level, using IDDSI guidelines, and for milk flow rate, using established flow testing methods: Similac Advance, Similac For Spit-Up, Enfamil Infant, and Enfamil A.R. Analysis of variance was used to compare flow rates among formula types/preparations. Results Enfamil A.R. ready-to-feed was classified as IDDSI “slightly thick.” All other formula types/preparations were found to be IDDSI “thin” liquids. The standard infant formulas (Similac Advance and Enfamil Infant) had comparable flow rates to each other, regardless of preparation (ready-to-feed and powder). The gastroesophageal reflux–specific formulas (Similac For Spit-Up and Enfamil A.R.) had slower flow rates than the standard formulas; within this category, there were significant differences in flow rates between ready-to-feed and powder. Enfamil A.R. powder had the slowest flow rate, but was the most variable. Conclusion For infants with difficulty coordinating sucking, swallowing, and breathing, clinicians and parents should consider the impact that changes to infant formula type and preparation may have on the infant's ability to safely feed.

Assessment of the impact of water parameters on the flow rate of ceramic pot filters in a long-term experiment

2015 ◽  
Vol 15 (6) ◽  
pp. 1425-1432 ◽  
Author(s):  
C. Salvinelli ◽  
A. C. Elmore
Keyword(s):  
Flow Rate ◽  
Water Production ◽  
Premature Failure ◽  
Initial Flow ◽  
Flow Rates ◽  
Treated Water ◽  
Long Term Study ◽  
The Impact ◽  
The Relationship

Poor water quality is a major contributing factor to disease in developing countries. Silver-coated ceramic pot filters (CPFs) are a relatively common form of household water treatment system (HWTS) representing an effective and sustainable technology for poor communities. Water production seems to be the major limiting factor of the CPF's lifetime and sustainability since low flow rates do not produce an adequate daily volume of treated water. This paper describes a long-term study of CPF flow rates under controlled conditions using three different water sources. The relationship between water characteristics and flow rate was assessed with the intent of identifying the principal parameters that impact CPF water production. The study concluded that turbidity seems to be the principal indicator in determining CPF lifetime in terms of quantity of treated water. There is no evidence that biological activity also contributes to premature failure of CPFs and the data did not indicate that chemical precipitation is responsible for the filter clogging. Manufacturers commonly conduct initial flow rate tests using clear water as a measure of quality assurance. However, the relationship between initial flow rate and average flow rate during the lifetime of the CPF should be further studied.

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