Priyabrata Pattanaik

Experimental and simulated study of electrical behaviour of ZnO film deposited on Al substrate for device applications

Abstract In this paper, zinc oxide (ZnO) film has been deposited on Al substrate by chemical wet and dry technique which is just a simple modified version of the dip coating method. In this method, it is possible to precisely control the immersion and withdrawal speed, with drying as well as annealing at the same time. The polycrystalline nature of ZnO has been confirmed by X-ray diffraction (XRD) analysis. The XRD analysis clearly indicates that some percentage of Al diffuses into the ZnO matrix at its interface region; hence it affects mobility of the sample. Hall measurement indicates the ZnO semiconductor as n-type. I–V characteristic of the sample shows that the contact is Ohmic and it can be used as a sensor at low potential value. The mobility decreases with increase in temperature. The simulation study carried out for I–V and mobility through simulation using ATLAS (SILVACO) software confirms that the experimental and simulation results are in close agreement with respect to the I–V characteristic and the mobility.

Performance analysis of ZnO-based ultrasonic MEMS transducer used for blind person navigation

Navigation is not an easy task especially without using eye. Creatures like bats and dolphins are navigated by creating ultrasonic wave. The sensory organs help them to create and sense the path without visualising it. This paper imitates these creatures to propose an ultrasonic-based MEMS transducer for blind person navigation. MEMS-based acoustic transducers commonly employ the piezoelectric material. This model has been designed by using non-toxic and low cost compound like zinc oxide (ZnO) using COMSOL multiphysics. 2D axis-symmetrical model geometry is designed to imitate like sensory organ to sense the obstacle present two metres away from it. An optimised voltage of five volts and frequency of 20.103 KHz is applied to the proposed model to create ultrasonic wave. Further, the wave propagation in the air medium is analysed by using 3D partial differential equation. The pressure waves are studied during transmitting and receiving time. The rebounded wave from the obstacle to the transducer is converted to 30.2 mV by the proposed model. The von-misses stress is carried out to study the pressure on transducer surface.

Preparation of TiO 2 film on Ag and Al electrode for electrochemical bio-sensing application

In this present, work, titanium dioxide (TiO2) deposited on Ag and Al electrodes were fabricated by sol-gel chemical wet and dry (CWD) method to detect urea. The formation of the polycrystalline TiO2 deposited on Ag and Al substrates were confirmed by X-ray diffraction (XRD) analysis. The XRD analyses of both the samples clearly indicated that some percentage of Ag and Al diffuses into the TiO2 matrix at its interface region. The nature of I-V characteristics showed by the TiO2 on Ag and Al wire electrodes are found to be Ohmic and is perfect to be used for electrochemical sensor or bio-sensor at very low potential value. The performance and response to various concentrations of urea solution and pH level were experimentally studied by using TiO2 coated on Ag and Al as working electrodes with respect to Ag as reference electrode.

A Simulation Approach to Study the Effect of Ultrasonic MEMS Based Receiver for Blood Glucose Sensing Applications

The accurate measurement of glucose level in the blood is an important task to prevent the progression of chronic disease like diabetes mellitus. This article proposes a simulation based approach to evaluate the ZnO-based ultrasonic piezoelectric microelectronics mechanical systems (MEMS) receiver for blood glucose sensing applications. Prior to the fabrication of the proposed biosensor, a simulation study is conducted to avoid the dissipation of valuabletime and cost. The potential of 1.6V with a 350-MHz frequency is applied to the transmitter section that has been placed on the surface of blood sample with a cylindrical geometry having diameter and height of 1 and 10mm, respectively. The surface and the radial displacement of the receiver section structure of the piezoelectric material with pressure and stress are studied in the blood medium. The simulation results reveal that, for different glucose density levels in the human blood, different pressure values are observed at the receiving end and that the respective pressure values are converted into voltages by using the piezoelectric principle. To verify the changes in the generated voltages, we have compared the glucose levels of blood samples using the proposed approach with the commercially available glucometer.