Different type of mechanisms of gas sensing, various factors that affect the mechanisms, ways to improve the gas sensitivity, state of the art of fabrication techniques and materials used are reviewed. The work also discusses a novel type of gas sensor derived based on the reviewed mechanisms and materials. The development of semiconductor-based gas sensors using tin oxide which is simple to implement, low cost and offering good stability and sensitivity is discussed. © 2016 IETE.

Velmathi G

Electronics

School of Electronics Engineering

Chennai Campus

Mohan S

Henry R.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

Analysis and Review of Tin Oxide-Based Chemoresistive Gas Sensor

IETE Technical Review

In the last decade, light has been increasingly used as an innovative optical stimulation tool for therapeutic and diagnostic neuronal applications. Light-emitting diodes (LEDs) have emerged as a suitable light source. Such implantable systems include small-dimensional diodes as light sources for nerve stimulation in tandem with neural electrodes. All such devices generate a huge amount of heat which may limit their functionality and characteristic behaviour. Heat generated, if not properly engineered to dissipate through the design, may cause serious damages to biological tissue especially in the case of brain implants. The main purpose of the proposed project is to analyse the thermal behaviour of Optrodes operating in the brain environment and thermal management techniques for such a device. The work started with the analysis of heat dissipation from an LED and methods to insulate the brain tissues. Finite element method simulation is done to investigate thermal characteristics of implantable Optrodes. In order to verify the simulated results, an Optrode structure is developed on a standard substrate. The temperature of the Optrode is measured experimentally in operating mode in environmental conditions similar to brain tissues. The results from simulation, experiment, and analytical calculations are compared for validation. Finally, optical characteristics of LED are measured to correlate the thermal behaviour of the system. From the results obtained, a technically feasible thermal management system for such an Optrode design is suggested. © 2020, © 2020 IETE.

IETE Journal of Research

Thermal Analysis of Light Source for Optogenetics Experiments

The proposed work studies the synthesis, structural, and sensitivity of tin oxide films deposited by sputtering for a gas sensor. This includes an analysis of a tin oxide film doped with noble metal palladium. Gas sensitivity of the deposited layer is analysed as per the deposition parameters such as the thickness of the film, substrate temperature, argon–oxygen ratio of the sputtering environment, and duration and doping metal weight percentage into the tin oxide films and the results obtained are explained. © 2016 IETE.

Journal	IETE Technical Review
Publisher	Informa UK Limited
ISSN	0256-4602
Open Access	No