Development of a microfluidic device for measuring an electric signal of a nerve cell within a micro-channel

2004 ◽  
Vol 2004 (0) ◽  
pp. 86
Author(s):  
N Kumamoto ◽  
T Yagi ◽  
T Yasuda
Keyword(s):  
Nerve Cell ◽  
Microfluidic Device ◽  
Electric Signal ◽  
Micro Channel

scholarly journals Negative Pressure Provides Simple and Stable Droplet Generation in a Flow-Focusing Microfluidic Device

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 662
Author(s):  
Nikita A. Filatov ◽  
Anatoly A. Evstrapov ◽  
Anton S. Bukatin
Keyword(s):  
Microfluidic Device ◽  
Negative Pressure ◽  
Low Cost ◽  
Control Valve ◽  
Droplet Microfluidics ◽  
Droplet Generation ◽  
Electric Signal ◽  
Absolute Pressure ◽  
Flow Focusing ◽  
Wide Range

Droplet microfluidics is an extremely useful and powerful tool for industrial, environmental, and biotechnological applications, due to advantages such as the small volume of reagents required, ultrahigh-throughput, precise control, and independent manipulations of each droplet. For the generation of monodisperse water-in-oil droplets, usually T-junction and flow-focusing microfluidic devices connected to syringe pumps or pressure controllers are used. Here, we investigated droplet-generation regimes in a flow-focusing microfluidic device induced by the negative pressure in the outlet reservoir, generated by a low-cost mini diaphragm vacuum pump. During the study, we compared two ways of adjusting the negative pressure using a compact electro-pneumatic regulator and a manual airflow control valve. The results showed that both types of regulators are suitable for the stable generation of monodisperse droplets for at least 4 h, with variations in diameter less than 1 µm. Droplet diameters at high levels of negative pressure were mainly determined by the hydrodynamic resistances of the inlet microchannels, although the absolute pressure value defined the generation frequency; however, the electro-pneumatic regulator is preferable and convenient for the accurate control of the pressure by an external electric signal, providing more stable pressure, and a wide range of droplet diameters and generation frequencies. The method of droplet generation suggested here is a simple, stable, reliable, and portable way of high-throughput production of relatively large volumes of monodisperse emulsions for biomedical applications.

Generation and Transport of Bubbles in a Microfluidic Device

2008 ◽  
Author(s):  
Renqiang Xiong ◽  
Jacob N. Chung
Keyword(s):  
Silicon Wafer ◽  
Microfluidic Device ◽  
High Speed ◽  
Micro Channel ◽  
Bubble Generation ◽  
Air Bubble ◽  
Micro Scale ◽  
Bubble Transport

In this paper we used high speed recording to characterize segmented micro-scale air bubble generation in a T-junction and bubble transport in a serpentine micro-channel fabricated in a standard silicon wafer.

scholarly journals Microfluidic Devices for Behavioral Screening of Multiple Zebrafish Larvae: Design Investigation Process

2021 ◽  
Author(s):  
Arezoo Khalili ◽  
Ellen van Wijngaarden ◽  
khaled Youssef ◽  
Georg Zoidl ◽  
Pouya Rezai
Keyword(s):  
Microfluidic Device ◽  
Flow Behavior ◽  
Beat Frequency ◽  
Microfluidic Devices ◽  
Response Duration ◽  
Lessons Learned ◽  
Electric Signal ◽  
Testing Time ◽  
Multiple Parameters ◽  
Zebrafish Larvae

Microfluidic devices have been introduced for phenotypic screening of zebrafish larvae in both fundamental and pre-clinical research. One of the remaining challenges for the broad use of microfluidic devices is their limited throughput, especially in behavioural assays. Previously, we introduced the tail locomotion of a semi-mobile zebrafish larva evoked on-demand with electric signal in a microfluidic device. Here, we report the lessons learned for increasing the number of specimens from one to four larvae in this device. Multiple parameters including loading and testing time per fish and loading and orientation efficiencies were refined to optimize the performance of modified designs. Simulations of the flow and electric field within the final device provided insight into the flow behavior and functionality of traps when compared to previous single-larva devices. Outcomes led to a new design which decreased the testing time per larva by approximately 60%. Further, loading and orientation efficiencies increased by more than 80%. Critical behavioural parameters such as response duration and tail beat frequency were similar in both single and quadruple-fish devices. The optimized microfluidic device has significant advantages for greater throughput and efficiency when behavioral phenotyping is required in various applications, including chemical testing in toxicology and gene screening.

scholarly journals Design and fabrication of a holey fiber microfluidic device with transverse micro-channel

2014 ◽  
Vol 6 (2) ◽  
Author(s):  
Dora Juan Juan Hu ◽  
Ying Cui ◽  
Jun Long Lim ◽  
Perry Ping Shum ◽  
Georges Humbert ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Micro Channel ◽  
Holey Fiber

scholarly journals Zebrafish Larva’s Response and Habituation to Electric Signal: Effects of Voltage, Current and Pulsation Studied in a Microfluidic Device

2021 ◽  
Author(s):  
Arezoo Khalili ◽  
Ellen van Wijngaarden ◽  
Georg Zoidl ◽  
Pouya Rezai
Keyword(s):  
Electric Current ◽  
Microfluidic Device ◽  
Voltage Drop ◽  
Light Stimulus ◽  
Beat Frequency ◽  
Phenotypic Characterization ◽  
Electric Signal ◽  
Electric Response ◽  
Current Direction ◽  
Electric Pulses

We previously showed that electric current can cause zebrafish larvae to move towards the anode pole along a microchannel. For a semi-mobile larva, we observed that zebrafish response to electricity depended on the current magnitude. The effects of electric signal direction, voltage magnitude and habituation to repeated exposures to electric pulses were not characterized. Here, this knowledge gap was addressed by exploiting these parameters in a microfluidic device with a head-trap to immobilize a zebrafish larva and a downstream chamber for tail movement and phenotypic characterization of response duration (RD) and tail beat frequency (TBF). We first assessed larvae’s response to electric current direction (at 3µA) and voltage magnitude. Changing the current direction significantly altered the RD and TBF with long and low-frequency responses seen when the anode was positioned at larvae’s tail. The electric voltage drop across the fish body had a significant effect on larvae’s locomotion with long RD and low TBF observed at 5.6V in the range of 1.3-9V. We also demonstrated that the zebrafish locomotor response to repeated 3µA current pulses diminished with dependency on the interstimulus interval. However, the diminished response was fully recovered after a 5-min resting period or introduction of a novel light stimulus (i.e. habituation-dishabituation strategy). Therefore, electric response suppression in zebrafish was attributed to the habituation as a form of non-associative learning. Our microfluidic platform has broad application potential in behavioral neuroscience to study cognitive phenotypes, fundamental studies on the biological roots of electric response, and pharmacological screening.

A Microfluidic Culturing System for Observation of Free-Floating Microorganisms

2013 ◽  
Author(s):  
Katsuo Mogi ◽  
Yasuhiko Sugii ◽  
Teruo Fujii ◽  
Yoichiro Matsumoto
Keyword(s):  
Microfluidic Device ◽  
Botryococcus Braunii ◽  
Channel Structure ◽  
The Other ◽  
Micro Channel ◽  
Continuous Observation ◽  
Strong Fluorescence ◽  
Time Condition ◽  
Other Hand ◽  
Ethanol Toxicity

We observed the effect of the ethanol toxicity on individual cells of Botryococcus braunii (B. braunii) in microchannel environment. For continuous observation of B. braunii in microchannel environment, a microfluidic device which has a specific channel structure was developed. By using the channel structure, microorganisms were sorted by their size and captured on the corresponding area in the channel. In the experiment, suspension of B. braunii with DAPI was injected into the device for the cell capturing in the experiment. Following the cell capturing, ethanol with DAPI 0.5% was injected into the channel for 60 minutes. Damaged cells were confirmed by their deformation and the fluorescence of DAPI. The strong fluorescence of DAPI was confirmed after 20 minutes. On the other hand, the fluorescence of the chloroplast became weak in contrast to the fluorescence of DAPI. We successfully confirmed the time condition of exposing B. braunii to ethanol in the micro channel.

scholarly journals A Y-Shaped Microfluidic Device to Study the Combined Effect of Wall Shear Stress and ATP Signals on Intracellular Calcium Dynamics in Vascular Endothelial Cells

2016 ◽  
Author(s):  
Zong-Zheng Chen ◽  
Zheng-Ming Gao ◽  
De-Pei Zeng ◽  
Bo Liu ◽  
Yong Luan ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Intracellular Calcium ◽  
Microfluidic Device ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial ◽  
Micro Channel ◽  
Calcium Dynamics ◽  
Intracellular Calcium Dynamics

The intracellular calcium dynamics in vascular endothelial cells (VECs) in response to wall shear stress (WSS) and/or adenosine triphosphate (ATP) have been commonly regarded as an important factor in regulating VEC function and behavior including proliferation, migration and apoptosis. However, the effects of time-varying ATP signals have been usually neglected in the past investigations in the field of VEC mechanobiology. In order to investigate the combined effects of WSS and dynamic ATP signals on the intracellular calcium dynamic in VECs, a Y-shaped microfluidic device, which can provide the cultured cells on the bottom of its mixing micro-channel with stimuli of WSS signal alone and different combinations of WSS and ATP signals in one single micro-channel, is proposed. Both numerical simulation and experimental studies verify the feasibility of its application. Cellular experimental results also suggest that a combination of WSS and ATP signals rather than a WSS signal alone might play a more significant role in VEC Ca2+ signal transduction induced by blood flow.

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