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The aim of this paper is to propose a new method for the better assessment of cytoplasm conductivity, which is critical to the development of electroporation protocols as well as insight into fundamental mechanisms underlying electroporation. For this goal, we propose to use nanosecond electrical pulses to bypass the complication of membrane polarization(More)
A compact model is proposed to facilitate the design and simulation of the control waveform of RF microelectromechanical systems (MEMS) capacitive switches with electrostatically actuated membranes. Following conventional approaches, the pull-in motion of a membrane is simulated by an L-R-C network. However, the present model deviates from conventional(More)
This paper compares the characteristics of an RF microelectromechanical systems (MEMS) capacitive switch with a molybdenum membrane versus that of a switch with similar construction but with an aluminum membrane. In comparison, the molybdenum switch exhibits a significantly reduced sensitivity to ambient temperature change so that its pull-in voltage varies(More)
To resolve the dilemma of cell clogging or solution parasitics encountered by Coulter counters and to evolve a general-purpose electrical detection technique, we used broadband microwave measurements to overcome electrode polarization, ac dielectrophoresis to precisely place cells between narrowly spaced electrodes, and relatively wide microfluidic channels(More)
This paper reports on the first RF MEMS capacitive switch with a capacitance ratio of 130 that is stable almost up to 3 W of RF power. From an RF point of view the device behaves as a shunt capacitive switch, but employs an ohmic contact between the movable membrane and a floating metal deposited on the dielectric-coated stationary electrode, which is used(More)
— A CMOS control circuit capable of closed-loop capacitance sensing and control of RF MEMS switches was designed, fabricated, and tested. The control was based on fine-tuning the magnitude of the bias voltage of the switches according to the difference between sensed and targeted capacitances. Intelligence could be programmed by periodically alternating the(More)
Using a novel broadband microchamber, electrical detection of live and dead single cells was demonstrated. Tests on Jurkat cells showed that live cells had lower resistance but higher capacitance than that of dead cells. The test results were compared with the limited literature on broadband electrical detection of single cells and the discrepancies, both(More)
This paper presents the design of a Ka-band phase shifter comprising a slow-wave structure that tightly wraps around three closely spaced MEMS capacitive switches. The switches are of proven design and reliability, except some switches have a gap in their stationary electrodes. This novel feature has negligible effect on electromechanical operation but(More)
A nanopore test circuit is proposed for single-strand DNA sequencing, which allows real-time sensing of the electric conductance of individual sections of a DNA strand as it is pulled through the nanopore by an electric current at a controlled speed. The test circuit is based on a planar microchamber with a nanochannel drilled through its multilayer(More)
For the first time, both pull-in and release transients were characterized under high RF power levels on electrostatically actuated capacitive switches that exhibited little ambient temperature dependence under small-signal conditions. In spite of the complication of buckling, thermal resistances and time constants were extracted for both pulled-in and(More)