A microfluidics-integrated impedance/surface acoustic resonance tandem sensor

We demonstrate a dual sensor concept for lab-on-a-chip in-liquid sensing through integration of surface acoustic wave resonance (SAR) sensing with electrochemical impedance spectroscopy (EIS) in a single device. In this concept, the EIS is integrated within the building blocks of the SAR sensor, but features a separate electrical port. The two-port sensor was designed, fabricated, and embedded in a soft polymer microfluidic delivery system, and subsequently characterized. The SAR-EIS tandem sensor features low cross-talk between SAR and EIS ports, thus promoting non-interfering gravimetric and impedimetric measurements. The EIS was characterized by means of the modified Randle\u27s cell lumped element model. Four sensitive parameters could be established from the tandem sensor readout, and subsequently employed in a proof of principle study of liposome layers and their interaction with Ca2+ ions, leading to transformation into molecular film structures. The associated shift of the sensing quantities is analysed and discussed. The combination of impedimetric and gravimetric sensing quantities provides a unique and detailed description of physicochemical surface phenomena as compared to a single mode sensing routine

A one-port SAW in-liquid sensor platform: Design and fabrication

SH-SAW In-liquid sensors have been explored extensively in recent decades. They propose an ability to work at higher frequencies, than the well-known QCM, with the aim to reduce the size and ease the integration in sensor arrays. So far SH-SAW liquid phase sensors are designed in two-port delay line configurations because of the need to protect the IDT from the conductive and dielectric loads from the liquid. A compact one-port resonant SH-SAW liquid sensor is yet to be developed as an alternative of QCM at high frequencies

COMSOL Modeling of Hall Sensors Efficiency

In this paper we present a finite element analysis routine for modeling of semiconductor Hall sensors. Their efficiency is studied varying the base semiconductor material. More specifically, 2D COMSOL semi-conductor model is initially employed to extract the properties of the conductive channel. Subsequently a 3D COMSOL DC model is used to perform the studies regarding the Hall sensor efficiency. Hall sensors of identical topology and doping levels are studied in a comparative manner

Design and fabrication of efficient piezo-MEMS voltage transformers

RF Voltage transformers operating in one of the ISM frequency bands have recently been demanded in emerging low-power applications, such as wake-up radios in wireless networks, remotely triggered switches, stand-by units in home electronics, etc. S0 Lamb wave resonant (LWR) transformers have been first proposed. Later, SAW transformers designed as \u27degenerated\u27 CRF have been proposed. Here we demonstrate a tetherless design of efficient LWR transformer and discuss the abilities to boost the voltage gain

Styrene maleic acid copolymer induces pores in biomembranes

We investigated the interactions between styrene–maleic acid (SMA) copolymers and phospholipid bilayers, using confocal microscopy and surface acoustic wave resonance (SAR) sensing. For the first time we experimentally observed and followed pore formation by SMA copolymers in intact supported bilayers and unilamellar vesicles, showing that fluorescein, a water-soluble organic compound with a mean diameter of 6.9 Å, can traverse the membrane. Our findings are in agreement with recent theoretical predictions, which suggested that SMA copolymers may insert along the plane of the bilayer to form stable toroidal pores