A micro-mechanical compliant device for individual cell-stretching, compression, and in-situ force-measurement

Author(s):  
Somanna A. Kollimada ◽  
Sambuddha Khan ◽  
Sreenath Balakrishna ◽  
Shilpa Raju ◽  
Suma Matad ◽  
...  
Nano Select ◽  
2020 ◽  
Author(s):  
Florian Lauraux ◽  
Sarah Yehya ◽  
Stéphane Labat ◽  
Jean‐Sébastien Micha ◽  
Odile Robach ◽  
...  

1999 ◽  
Vol 121 (1) ◽  
pp. 126-132 ◽  
Author(s):  
D. O. Baun ◽  
R. D. Flack

A research pump intended for both flow visualization studies and direct measurement of hydrodynamic radial and axial forces has been developed. The impeller and the volute casing are constructed from Plexiglas which facilitates optical access for laser velocimetry measurements of the flow field both inside the impeller and in the volute casing. The pump housing is designed for flexibility allowing for each interchange of impellers and volute configurations. The pump rotor is supported by three radial magnetic bearings and one double acting magnetic thrust bearing. The magnetic bearings have been calibrated to characterize the force versus coil current and air gap relationship for each bearing type. Linear calibration functions valid for rotor eccentricities of up to 2/3 of the nominal bearing clearances and force level of ±58 N (13 lbf) and ±267 N (60 lbf) for the radial and axial bearings, respectively, were found. A detailed uncertainty analysis of the force calibration functions was conducted such that meaningful uncertainty bounds can be applied to in situ force measurements. Hysteresis and eddy current effects were quantified for each bearing such that their effect on the in situ force measurements could be assessed. By directly measuring the bearing reaction forces it is possible to determine the radial and axial hydraulic loads acting on the pump impeller. To demonstrate the capability of the magnetic bearings as active load cells representative hydraulic force measurements for a centered 4 vane 16 degree log spiral radial flow impeller operating in a single tongue spiral volute casing were made. At shut-off a nondimensional radial thrust of 0.084 was measured. A minimum nondimensional radial thrust of about 0.007 was observed at the nominal design flow. The nondimensional radial thrust increased to about 0.019 at 120 percent of design flow. The nondimensional axial thrust had a maximum at shut-off of 0.265 and decreased steadily to approximately 0.185 at 120 percent of design flow. Two regions of increasing axial thrust, in the flow range 75 to 100 percent of design flow, were observed. The measurements are compared to radial and axial force predictions using classical force models. The direct radial force measurements are compared to a representative set of radial force measurements from the literature. In addition, the directly measured radial force at design flow is compared to a single representative radial force measurement (obtained from the literature) calculated from the combination of static pressure and net momentum flux distribution at the impeller exit.


2013 ◽  
Vol 133 (12) ◽  
pp. 350-357
Author(s):  
Yuta Nakashima ◽  
Ryo Monji ◽  
Katsuya Sato ◽  
Kazuyuki Minami

Author(s):  
Rebecca H East ◽  
Jonathan J Noble ◽  
Richard A Arscott ◽  
Adam P Shortland

2019 ◽  
Author(s):  
Renjie Liao ◽  
Diego Mastroeni ◽  
Paul D. Coleman ◽  
Jia Guo

AbstractThe ability to perform highly sensitive and multiplexed in situ protein analysis is crucial to advance our understanding of normal physiology and disease pathogenesis. To achieve this goal, here we develop an approach using cleavable biotin conjugated antibodies and cleavable fluorescent streptavidin (CFS). In this approach, protein targets are first recognized by the cleavable biotin labeled antibodies. Subsequently, CFS is applied to stain the protein targets. Though layer-by-layer signal amplification using cleavable biotin conjugated orthogonal antibodies and CSF, the protein detection sensitivity can be enhanced by at least 10 fold, compared with the existing methods. After imaging, the fluorophores and the biotins unbound to streptavidin are removed by chemical cleavage. The leftover streptavidin is blocked by biotin. Upon reiterative analysis cycles, a large number of different proteins with a wide range of expression levels can be unambiguously detected in individual cell in situ.


2000 ◽  
Vol 6 (2) ◽  
pp. 115-132 ◽  
Author(s):  
P. Tiano ◽  
C. Filareto ◽  
S. Ponticelli ◽  
M. Ferrari ◽  
E. Valentini

Abstract In the field of conservation of monumental buildings actually a standard methodology is lacking, with which it is possible to determine with the same sensitivity and reliability the "stone hardness" both at the superficial surface and at larger depths (few centimetres), both in laboratory and in situ. The use of the drilling resistance to determine the stone hardness is a very recent application and few working outdoor devices exist. The objective of this work is to validate a new and improved system to assess the drilling resistance of stones. The DFMS is portable and a quasi non-destructive device for direct determination of the "cohesion" of stone materials through the determination of their drilling resistance. The best operational features of the prototype have been established together with the assessment of the sensitivity and reliability of the system.


Author(s):  
Nobuyoshi Fujimatsu ◽  
Isao Misu

New method and means are proposed to measure the skin friction force on an aerodynamic surface based on elastic deformations of silicon rubber and gel coatings. One of characteristics is soft and easy to deform. Object is coated by elastic polymeric film with known shear modulus. Two images between wind-on and wind-off are taken using the CCD camera. The displacement of coating is calculated from the correlation of two images. There are two ways to calibrate the skin friction force to the displacement of coatings. These methods are tested and compared to quantitative skin friction force measurement. One is based on measuring the characteristics of the polymeric film using visco-elastic measurement system. This way is called as a priori calibration. The other way is accomplished from the relation between the skin friction force measured by the PHF embedded on the object and the displacement around there and is known as In-situ method. Characteristics of the coatings such as the displacement and the time response can be easily controlled by the compounding ratio of hardener. We conduct the theoretical analysis for the elastic polymer film and propose the material properties of the coatings required to measure the surface skin friction in the wide range of flow speed. The skin friction over the plate is measured using this technique in various Reynolds number. The traditional measurement using the hot wire anemometry is conducted to validate this technique. The time averaged measurements of this technique are in good agreement with the traditional results. However, the unsteady characteristics of surface skin friction are not captured by the lack of time resolution of the CCD camera.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Seungman Park ◽  
Yoon Ki Joo ◽  
Yun Chen

Abstract We present a high-throughput microfluidics technique facilitating in situ measurements of cell mechanics parameters at the dorsal side of the cell, including molecular binding strengths, local traction forces, and viscoelastic properties. By adjusting the flow rate, the force magnitude exerted on the cell can be modulated ranging from ~14 pN to 2 nN to perturb various force-dependent processees in cells. Time-lapse images were acquired to record events due to such perturbation. The values of various mechanical parameters are subsequently obtained by single particle tracking. Up to 50 events can be measured simultaneously in a single experiment. Integrating the microfluidic techniques with the analytic framework established in computational fluid dynamics, our method is physiologically relevant, reliable, economic and efficient.


MRS Advances ◽  
2016 ◽  
Vol 1 (56) ◽  
pp. 3783-3788 ◽  
Author(s):  
Serap Aksu

ABSTRACTThe main objective of this report is to demonstrate novel engineering technologies to investigate regulatory mechanisms of systems immunology in a time-dependent and high-throughput manner. Understanding of immune system behavior is crucial for accurate prognosis of infections and identification of diseases at early stage. An ultimate goal of biomedical engineering is to develop predictive models of immune system behavior in tissue, which necessitates a comprehensive map of dynamic (time-dependent) input-output relationships at the individual cell level. Traditionally, biochemical analysis on the cell signaling is obtained from bulky cell ensembles which average over relevant individual cell response. The response consists firstly of signaling protein (cytokine) secretions which are released during a disease state and which are used to activate the immune system to respond to the disease. We investigate the cytokine secretion dynamics of a single immune cell in response to the stimulant using automated and comprehensive optofluidic platforms. These platforms enable survival and manipulation of single cells in compartments having compatible sizes with cells as well as provide precise control over the type, dose and time-course of the stimulant. The cytokine secretion dynamics of single cell are typically explained by measuring the types, rates, frequencies and concentrations of various cytokines. For the quantitative measurements, label free localized surface plasmon resonance (LSPR) based biosensor can be integrated within the microfluidic device. Microfluidic channels can confine secreted cytokines in compartments, minimize dilution effects and increase detection sensitivity for label free plasmonic biosensing. The direct application of LSPR to in-situ live cell function analysis is still in its infancy and use of such in-situ, real time, and label free biodetection will effortlessly provide high-throughput quantitative bioanalysis for understanding immune system behavior.


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