Development of Inverter Circuits with Dual Control Subchannel Areas of Integral CMOS Sensor Element

The use of an integrated sensor element as an addition of inverter, which converts the resistance of a sensitive element into the level of the output pulse signal, is investigated. Inverter circuits with different control options for sub-channel areas of MOS transistors are modeled in the LTSpice program. Based on the simulation results, dependencies graphs of the output signal amplitude on the resistance of a sensitive element and sensor’s sensitivity are drawn, and the shapes of the output signals are shown.

Improving the Room-Temperature Ferromagnetism in ZnO and Low-Doped ZnO:Ag Films Using GLAD Sputtering

ZnO and doped ZnO films with non-ferromagnetic metal have been widely used as biosensor elements. In these studies, the electrochemical measurements are explored, though the electrical impedance of the system. In this sense, the ferromagnetic properties of the material can be used for multifunctionalization of the sensor element using external magnetic fields during the measurements. Within this context, we investigate the room-temperature ferromagnetism in pure ZnO and Ag-doped ZnO films presenting zigzag-like columnar geometry. Specifically, we focus on the films’ structural and quasi-static magnetic properties and disclose that they evolve with the doping of low-Ag concentrations and the columnar geometry employed during the deposition. The magnetic characterization reveals ferromagnetic behavior at room temperature for all studied samples, including the pure ZnO one. By considering computational simulations, we address the origin of ferromagnetism in ZnO and Ag-doped ZnO and interpret our results in terms of the Zn vacancy dynamics, its substitution by an Ag atom in the site, and the influence of the columnar geometry on the magnetic properties of the films. Our findings bring to light an exciting way to induce/explore the room-temperature ferromagnetism of a non-ferromagnetic metal-doped semiconductor as a promising candidate for biosensor applications.

Carboxylated Graphene Nanoribbons for Highly-Selective Ammonia Gas Sensors: Ab Initio Study

The character and degree of influence of carboxylic acid groups (COOH) on the sensory properties (particularly on the chemoresistive response) of a gas sensor based on zigzag and armchair graphene nanoribbons are shown. Using density functional theory (DFT) calculations, it is found that it is more promising to use a carboxylated zigzag nanoribbon as a sensor element. The chemoresistive response of these nanoribbons is higher than uncarboxylated and carboxylated nanoribbons. It is also revealed that the wet nanoribbon reacts more noticeably to the adsorption of ammonia. In this case, carboxyl groups primarily attract water molecules, which are energetically favorable to land precisely on these regions and then on the nanoribbon’s basal surface. Moreover, the COOH groups with water are adsorption centers for ammonia molecules. That is, the carboxylated zigzag nanoribbon can be the most promising.

Effects of organic additives on the microstructural, rheological and electrical properties of silver paste for LTCC applications

Zinc(II) phthalocyanine (Zn(II)Pc) molecule was the first time prepared onto three different substrates utilizing Langmuir-Blodgett (LB) deposition technique to investigate its vapor sensing abilities and some optical properties. We utilized five different and well-known techniques to control monolayer quality of Zn(II)Pc LB film. The obtained the thickness and refractive index values for Zn(II)Pc LB film with coated at different layers vary from 3.2 to 10.9 nm and from 1.42 to 1.71, respectively. The sensing properties were investigated by exposing the Zn(II)Pc-based mass or optical sensor to some organic vapors. Kinetic results presented that this Zn(II)Pc material is a good candidate as a sensor element with a fast and reversible response for dichloromethane sensing devices.

In-Situ Spectroelectrochemical Study of Conductive Polyaniline Forms for Sensor Applications

Our contribution focuses on a correlative study of polyaniline (PANI) electropolymerisation and UV/VIS spectroscopy. PANI was prepared via electro-oxidation using a potentiodynamic method on commercial gold screen-printed electrodes (Au-SPE). By using an in-situ spectroelectrochemical method, the development of the polymer was observed from monomer, monomer oxidation to final polymer formation and its transformations between the oxidation forms. The results confirm the spontaneous doping of the polymer during the polymerisation, the instability of leucoemeraldine form in air and its two-stage oxidation to emeraldine form. The final conductive PANI deposited on Au-SPE will be used as sensor element for the detection of toxic organic compounds.