scholarly journals Integrating magnetic capabilities to intracellular chips for cell trapping

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
María Isabel Arjona ◽  
Consuelo González-Manchón ◽  
Sara Durán ◽  
Marta Duch ◽  
Rafael P. del Real ◽  
...  
Keyword(s):  
Proof Of Concept ◽  
Promising Technique ◽  
Magnetic Manipulation ◽  
Biochemical Sensors ◽  
Cell Trapping ◽  
Silicon Chips ◽  
Enhanced Sensitivity ◽  
Electrical Devices ◽  
Cell Enrichment ◽  
Mechanical Sensors

AbstractCurrent microtechnologies have shown plenty of room inside a living cell for silicon chips. Microchips as barcodes, biochemical sensors, mechanical sensors and even electrical devices have been internalized into living cells without interfering their cell viability. However, these technologies lack from the ability to trap and preconcentrate cells in a specific region, which are prerequisites for cell separation, purification and posterior studies with enhanced sensitivity. Magnetic manipulation of microobjects, which allows a non-contacting method, has become an attractive and promising technique at small scales. Here, we show intracellular Ni-based chips with magnetic capabilities to allow cell enrichment. As a proof of concept of the potential to integrate multiple functionalities on a single device of this technique, we combine coding and magnetic manipulation capabilities in a single device. Devices were found to be internalized by HeLa cells without interfering in their viability. We demonstrated the tagging of a subpopulation of cells and their subsequent magnetic trapping with internalized barcodes subjected to a force up to 2.57 pN (for magnet-cells distance of 4.9 mm). The work opens the venue for future intracellular chips that integrate multiple functionalities with the magnetic manipulation of cells.

scholarly journals Eye-recognizable and repeatable biochemical flexible sensors using low angle-dependent photonic colloidal crystal hydrogel microbeads

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mio Tsuchiya ◽  
Yuta Kurashina ◽  
Hiroaki Onoe
Keyword(s):  
Colloidal Crystal ◽  
Alcoholic Beverages ◽  
Structural Color ◽  
Proof Of Concept ◽  
Stimuli Responsive ◽  
Biochemical Sensors ◽  
Flexible Sensors ◽  
Sensor Temperature ◽  
Ethanol Sensing ◽  
User Friendly

AbstractThis paper presents eye-recognizable and repeatable biochemical flexible sensors using low angle-dependent stimuli-responsive photonic colloidal crystal hydrogel (PCCG) microbeads. Thanks to the stimuli-responsive PCCG microbeads exhibiting structural color, users can obtain sensing information without depending on the viewing angle and the mechanical deformation of the flexible sensor. Temperature-responsive PCCG microbeads and ethanol-responsive PCCG microbeads were fabricated from a pre-gel solution of N-isopropylacrylamide (NIPAM) and N-methylolacrylamide (NMAM) by using a centrifuge-based droplet shooting device (CDSD). As a proof-of-concept of thin and flexible biochemical sensors, temperature- and ethanol-sensing devices were demonstrated. By comparing the structural color of the stimuli-responsive PCCG microbeads and the color chart of the device, sensing information, including skin temperature of the human body and ethanol concentration in alcoholic beverages, was obtained successively. We expect that our device design using low angle-dependent stimuli-responsive PCCG microbeads would contribute to the development of user-friendly biochemical sensor devices for monitoring environmental and healthcare targets.

scholarly journals Bifurcation-enhanced ultrahigh sensitivity of a buckled cantilever

2018 ◽  
Vol 115 (12) ◽  
pp. 2884-2889 ◽  
Author(s):  
Sangmin An ◽  
Bongsu Kim ◽  
Soyoung Kwon ◽  
Geol Moon ◽  
Manhee Lee ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
High Sensitivity ◽  
Single Shot ◽  
Nonlinear Phenomenon ◽  
Ambient Conditions ◽  
Research Areas ◽  
Enhanced Sensitivity ◽  
Shot Detection ◽  
Mechanical Sensors

Buckling, first introduced by Euler in 1744 [Euler L (1744) Opera Omnia I 24:231], a sudden mechanical sideways deflection of a structural member under compressive stress, represents a bifurcation in the solution to the equations of static equilibrium. Although it has been investigated in diverse research areas, such a common nonlinear phenomenon may be useful to devise a unique mechanical sensor that addresses the still-challenging features, such as the enhanced sensitivity and polarization-dependent detection capability. We demonstrate the bifurcation-enhanced sensitive measurement of mechanical vibrations using the nonlinear buckled cantilever tip in ambient conditions. The cantilever, initially buckled with its tip pinned, flips its buckling near the bifurcation point (BP), where the buckled tip becomes softened. The enhanced mechanical sensitivity results from the increasing fluctuations, unlike the typical linear sensors, which facilitate the noise-induced buckling-to-flipping transition of the softened cantilever. This allows the in situ continuous or repeated single-shot detection of the surface acoustic waves of different polarizations without any noticeable wear of the tip. We obtained the sensitivity above 106 V(m/s)−1, a 1,000-fold enhancement over the conventional seismometers. Our results lead to development of mechanical sensors of high sensitivity, reproducibility, and durability, which may be applied to detect, e.g., the directional surface waves on the laboratory as well as the geological scale.

scholarly journals Phononic Crystal Sensors: A New Class of Resonant Sensors—Chances and Challenges for the Determination of Liquid Properties

2021 ◽  
Vol 7 ◽  
Author(s):  
Ralf Lucklum ◽  
Nikolay Mukhin ◽  
Bahram Djafari Rouhani ◽  
Yan Pennec
Keyword(s):  
Chemical Sensor ◽  
Phononic Crystal ◽  
Frequency Resolution ◽  
Liquid Volume ◽  
Mechanical Resonator ◽  
Resonant Sensors ◽  
Enhanced Sensitivity ◽  
Acoustic Dissipation ◽  
Mechanical Sensors ◽  
2D And 3D

Resonant mechanical sensors are often considered as mass balance, which responds to an analyte adsorbed on or absorbed in a thin sensitive (and selective) layer deposited on the surface of the resonant device. In a more general sense, the sensor measures properties at the interface of the mechanical resonator to the medium under inspection. A phononic crystal (PnC) sensor employs mechanical resonance as well; however, the working principle is fundamentally different. The liquid medium under inspection becomes an integral part of the PnC sensor. The liquid-filled compartment acts as a mechanical resonator. Therefore, the sensor probes the entire liquid volume within this compartment. In both sensor concepts, the primary sensor value is a resonant frequency. To become an attractive new sensing concept, specifically as a bio and chemical sensor, the PnC sensor must reach an extraordinary sensitivity. We pay attention to the liquid viscosity, which is an important factor limiting sensitivity. The main part of our analysis has been performed on 1D PnC sensors, since they underlie the same material-related acoustic dissipation mechanisms as 2D and 3D PnC sensors. We show that an optimal relation of frequency shift to bandwidth and amplitude of resonance is the key to an enhanced sensitivity of the sensor-to-liquid analyte properties. We finally address additional challenges of 2D and 3D PnC sensor design concept. We conclude that the sensor should seek for a frequency resolution close to 10−6 the probing frequency, or a resolution with speed of sound approaching 1 mm s−1, taking water-based analytes as an example.

EXELFS Studies of Carbon Fibers

1990 ◽  
Vol 48 (2) ◽  
pp. 72-73
Author(s):  
V. Serin ◽  
K. Hssein ◽  
G. Zanchi ◽  
J. Sévely
Keyword(s):  
Carbon Fibers ◽  
Energy Analysis ◽  
Electron Excitation ◽  
Complex Structures ◽  
High Modulus ◽  
Promising Technique ◽  
X Ray ◽  
Fine Structures ◽  
X Ray Absorption

The present developments of electron energy analysis in the microscopes by E.E.L.S. allow an accurate recording of the spectra and of their different complex structures associated with the inner shell electron excitation by the incident electrons (1). Among these structures, the Extended Energy Loss Fine Structures (EXELFS) are of particular interest. They are equivalent to the well known EXAFS oscillations in X-ray absorption spectroscopy. Due to the EELS characteristic, the Fourier analysis of EXELFS oscillations appears as a promising technique for the characterization of composite materials, the major constituents of which are low Z elements. Using EXELFS, we have developed a microstructural study of carbon fibers. This analysis concerns the carbon K edge, which appears in the spectra at 285 eV. The purpose of the paper is to compare the local short range order, determined by this way in the case of Courtauld HTS and P100 ex-polyacrylonitrile carbon fibers, which are high tensile strength (HTS) and high modulus (HM) fibers respectively.

Direct measurement of electron-diffraction-pattern intensities using an energy loss spectrometer

1989 ◽  
Vol 47 ◽  
pp. 668-669
Author(s):  
A. G. Jackson ◽  
M. Rowe
Keyword(s):  
Thermal Effects ◽  
Dynamic Range ◽  
Scattering Amplitude ◽  
Dynamical Theory ◽  
Site Symmetry ◽  
Proof Of Concept ◽  
Parallel Acquisition ◽  
Kinematic Approximation ◽  
Speed Up ◽  
Structure Calculations

Diffraction intensities from intermetallic compounds are, in the kinematic approximation, proportional to the scattering amplitude from the element doing the scattering. More detailed calculations have shown that site symmetry and occupation by various atom species also affects the intensity in a diffracted beam. [1] Hence, by measuring the intensities of beams, or their ratios, the occupancy can be estimated. Measurement of the intensity values also allows structure calculations to be made to determine the spatial distribution of the potentials doing the scattering. Thermal effects are also present as a background contribution. Inelastic effects such as loss or absorption/excitation complicate the intensity behavior, and dynamical theory is required to estimate the intensity value.The dynamic range of currents in diffracted beams can be 104or 105:1. Hence, detection of such information requires a means for collecting the intensity over a signal-to-noise range beyond that obtainable with a single film plate, which has a S/N of about 103:1. Although such a collection system is not available currently, a simple system consisting of instrumentation on an existing STEM can be used as a proof of concept which has a S/N of about 255:1, limited by the 8 bit pixel attributes used in the electronics. Use of 24 bit pixel attributes would easily allowthe desired noise range to be attained in the processing instrumentation. The S/N of the scintillator used by the photoelectron sensor is about 106 to 1, well beyond the S/N goal. The trade-off that must be made is the time for acquiring the signal, since the pattern can be obtained in seconds using film plates, compared to 10 to 20 minutes for a pattern to be acquired using the digital scan. Parallel acquisition would, of course, speed up this process immensely.

CBED analysis of impurity distributions in AlN

1990 ◽  
Vol 48 (4) ◽  
pp. 214-215
Author(s):  
Daniel Callahan ◽  
G. Thomas
Keyword(s):  
Aluminum Nitride ◽  
Bulk Material ◽  
Strong Dependence ◽  
Lattice Parameter ◽  
Promising Technique ◽  
Nitride Ceramics ◽  
Surface Phases ◽  
Convergent Beam ◽  
Oxygen Impurities

Oxygen impurities may significantly influence the properties of nitride ceramics with a strong dependence on the microstructural distribution of the impurity. For example, amorphous oxygen-rich grain boundary phases are well-known to cause high-temperature mechanical strength degradation in silicon nitride whereas solutionized oxygen is known to decrease the thermal conductivity of aluminum nitride. Microanalytical characterization of these impurities by spectral methods in the AEM is complicated by reactions which form oxygen-rich surface phases not representative of the bulk material. Furthermore, the impurity concentrations found in higher quality ceramics may be too low to measure by EDS or PEELS. Consequently an alternate method for the characterization of impurities in these ceramics has been investigated.Convergent beam electron diffraction (CBED) is a promising technique for the study of impurity distributions in aluminum nitride ceramics. Oxygen is known to enter into stoichiometric solutions with AIN with a consequent decrease in lattice parameter.

Remote Echocardiography: Proof of Concept for Support of National Disasters, Combat and Humanitarian Mission

2002 ◽  
Author(s):  
Sheri Yvonne Nottestad Boyd ◽  
Linda L. Huffer ◽  
Terry D. Bauch ◽  
James L. Furgerson
Keyword(s):  
Proof Of Concept ◽  
Humanitarian Mission

Eyes and ears: Rejection and enhanced sensitivity to auditory and visual social cues

2003 ◽  
Author(s):  
Cynthia L. Pickett ◽  
Wendi L. Gardner ◽  
Megan Knowles
Keyword(s):  
Social Cues ◽  
Enhanced Sensitivity

Model, simulation and experiments for a Buoyancy Organic Rankine Cycle

2020 ◽  
Vol 92 (1) ◽  
pp. 10906
Author(s):  
Jeroen Schoenmaker ◽  
Pâmella Gonçalves Martins ◽  
Guilherme Corsi Miranda da Silva ◽  
Julio Carlos Teixeira
Keyword(s):  
Model Simulation ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Test Body ◽  
Working Fluid ◽  
Proof Of Concept ◽  
Energy Scenario ◽  
New Type ◽  
Fluid Reservoir

Organic Rankine Cycle (ORC) systems are increasingly gaining relevance in the renewable and sustainable energy scenario. Recently our research group published a manuscript identifying a new type of thermodynamic cycle entitled Buoyancy Organic Rankine Cycle (BORC) [J. Schoenmaker, J.F.Q. Rey, K.R. Pirota, Renew. Energy 36, 999 (2011)]. In this work we present two main contributions. First, we propose a refined thermodynamic model for BORC systems accounting for the specific heat of the working fluid. Considering the refined model, the efficiencies for Pentane and Dichloromethane at temperatures up to 100 °C were estimated to be 17.2%. Second, we show a proof of concept BORC system using a 3 m tall, 0.062 m diameter polycarbonate tube as a column-fluid reservoir. We used water as a column fluid. The thermal stability and uniformity throughout the tube has been carefully simulated and verified experimentally. After the thermal parameters of the water column have been fully characterized, we developed a test body to allow an adequate assessment of the BORC-system's efficiency. We obtained 0.84% efficiency for 43.8 °C working temperature. This corresponds to 35% of the Carnot efficiency calculated for the same temperature difference. Limitations of the model and the apparatus are put into perspective, pointing directions for further developments of BORC systems.

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