Article

Microchamber Setup Characterization for Nanosecond Pulsed Electric Field Exposure

Xlim Research Institute, Centre National de la Recherche Scientifique (CNRS)-University of Limoges, Limoges, France.
(Impact Factor: 2.35). 06/2011; 58(6):1656-62. DOI: 10.1109/TBME.2011.2108298
Source: PubMed

ABSTRACT

Intracellular structures of biological cells can be disturbed by exposure to nanosecond pulsed electric field (nsPEF). A microchamber-based delivery system mounted on a microscope setup for real-time exposure to nsPEF is studied in this paper. A numerical and experimental characterization of the delivery system is performed both in frequency and time domains. The microchamber delivery system presents a high impedance compared to classical 50 Ω loads. Its frequency behavior and limits are investigated using an in-house finite-difference time-domain (FDTD) simulator and through experimental measurements. High-voltage measurements for two nsPEF generators are carried out. The applied pulse voltage measured across the microchamber electrodes is ∼1 kV, corresponding to ∼10 MV/m electric fields in the microchamber. Depending on the nsPEF generator used, the measured pulse durations are equal to 3.0 and 4.2 ns, respectively. The voltage distribution provided by FDTD simulations indicates a good level of homogeneity across the microchamber electrodes. Experimental results include permeabilization of biological cells exposed to 3.0-ns, 10-MV/m PEFs.

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• "However, broadband measurement would be more desirable, so that live and dead cells can be separated at low frequencies [3] while cell types can be differentiated at high frequencies [4]. Further, nanosecond electric pulses, which are inherently broadband, may be used for nanoporation and subcellular probing without ionization or heating [5], [6]. Finally, to maintain cells in a fluid while minimizing microwave absorption, microfluidic channels must be used [3], [4]. "
Conference Paper: Broadband microchamber for electrical detection of live and dead biological cells
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ABSTRACT: A novel broadband microchamber for electrical detection of live and dead biological cells was designed, fabricated and tested. The microchamber was formed between a gold coplanar waveguide fabricated on a quartz slide and the microfluidic channels fabricated in a polydimethylsiloxane cover. The coplanar waveguide allowed broadband impedance matching and efficient cell trapping. The microfluidic channels delivered single cells precisely. Tests on Jurkat cells in both time and frequency domains showed that live cells had lower resistance but higher capacitance than that of dead cells.
Microwave Symposium Digest (IMS), 2013 IEEE MTT-S International; 01/2013
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• "The EO probe crystal material, associated with the EO probe's sensitivity, is well suited for the measurement of high E-fields. Compared with the current state of the art, this new EO probe can be particularly useful for the measurement of high-voltage nanosecond pulsed e-fields (nsPEF), such as those found in electroporation cuvettes [27], [28] or near planar electrodes [29] and the monitoring of innovative nsPEF-based therapies. "
Article: Electro-Optic Probe Adapted for Bioelectromagnetic Experimental Investigations
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ABSTRACT: In this paper, we present radio-frequency electromagnetic field characterization of an electrooptic (EO) probe. This probe is able to simultaneously measure temperature and one component of the electric field (e-field) in a continuous wave (CW) or in a pulsed regime. For this purpose, linearity, selectivity, and sensitivity measurements are performed in air and in a cuvette filled with a water solution. The media are exposed to 1800-MHz CW electromagnetic wave through a transverse electromagnetic cell. Numerical characterization is also performed using finite-difference time-domain simulations. The EO probe presents a dynamic range exceeding 70 dB. Selectivity up to 25 dB is measured, demonstrating the ability of the EO probe to measure one unique component of the e-field. The EO probe sensitivity is equal to 0.77 and to 0.18 $\hbox{V}\cdot\hbox{m}^{-1} \hbox{Hz}^{-1/2}$, in the air and in the water solution, respectively. This millimeter-sized EO probe is particularly suited for the measurement of ultrawide bandwidth and high-voltage e-fields up to a few megavolts per meter.
IEEE Transactions on Instrumentation and Measurement 07/2012; 61(7):2051-2058. DOI:10.1109/TIM.2012.2183034 · 1.79 Impact Factor
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• "In order to characterize the EO probe measurement capabilities, two 50-high voltage pulse generators were used. The first one, switched by laser (HLX-I, Horus Laser, France), delivered 2.6 ns duration pulses, up to 1.6 kV amplitude and 800 ps rise and fall times [8]. A second one delivered 10 ns duration pulses, up to 10 kV amplitude and 1 ns rise and fall times (FPG 10-1SM10, FID Technology, Germany). "
Article: "Simultaneous High Intensity Ultrashort Pulsed Electric Field and Temperature Measurements Using a Unique Electro-Optic Prob"
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ABSTRACT: High intensity nanosecond pulsed electric fields and temperature were simultaneously measured using a unique electro-optic (EO) probe. The measurements were performed in an electroporation cuvette with 4 mm electrode gap and filled with a buffered salt solution. High voltage generators delivering 2.6 and 10 ns duration pulses with different pulses shape and intensity were investigated. The EO probe linearity was characterized up to 2 MV/m. The temperature measurement uncertainty was found to be less than 22 mK. Excellent measurement abilities were achieved with this EO probe showing its suitability for bioelectromagnetic experiments and particularly for wideband high intensity field applications.
IEEE Microwave and Wireless Components Letters 03/2012; 22(3):153-155. DOI:10.1109/LMWC.2012.2185840 · 1.70 Impact Factor