On the Realization of Photo-conductive Paints

In a country like India where the sunlight is available throughout the year, a large opportunity awaits in realizing it to the full potential. Very large scale projects are being undertaken by the Government to realize this goal, and the electrification of the Cochin Airport through solar cells is the finest example.

When it comes to solar power, the main challenge lies in the cost of installation. People seldom look into its long time value and are often caught in huge investment they have to make. In this scenario, it is vital, that some cost cutting technology come to help. And one proposal here is to develop a photo-conductive paint. The idea here is to develop a paint, with a chemical composition such that, it can absorb the ambient sunlight. The paint shall be composed of nano-particles which will in directly help in the conduction of the electricity.

A proposed idea helps you to apply the paint such that it can supplement the power line to your home.

Courtesy : http://www.stewmac.com/

eNose - Design, Applications and Challenges

This article is a republished version of the Technical Article Board at SSET

Abstract

Sensors are widely used today to collect local databases on various parameters. In this article, a sensor which can measure olfactory(smell) signals is presented. The eNose or the Electronic Nose is a biologically inspired sensor, having origins in the functioning of the mammalian olfactory system. A review of the various sensing techniques along with the classification methods and applications are presented.

Introduction

The term ``electronic nose" was coined in 1988 by Gardner and Bartlett wherein they defined e-nose (EN) as ``an instrument which comprises an array of electronic chemical sensors with partial specificity and appropriate pattern recognition system, capable of recognizing simple, or complex odours". The design of the sensor replicates the functioning of the mammalian olfactory system, although it has some limitations. For instance, EN's are more application specific, that is the sensor available for bio-sensing cannot be employed for food testing or environment monitoring. Recently, chemical based sensors are employed in measuring food quality and in select beverages and fast foods. The figure below illustrates the broad parts of the eNose.

How it is done : Components that are used

The eNose consists of the following components :

• Multiple Sensor Array
• Data Acquisition System
• Pattern Recognition System

There are different sensing mechanisms for the functioning of the eNose, viz. Optical, Mass and Ion Mobility based, Gas Chromatography based, Infrared Spectroscopy based, Chemical Sensors. Of these the Chemical sensors are the most popular and widely employed, as it is possible to tailor various parameters and due to its close resemblance to mammalian olfaction. These are again classifies as MOS, MOSFET, surface and bulk acoustic wave, and conductive polymers.

Role of Nanomaterials

The preferred choice of sensor is to employ nano-structures which offer many advantages such as low cost, compact size, low power consumption, and faster response. With the advancement in microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS) very large-scale integration (VLSI), and nanoscience various novel nanostructures are successfully being employed in the fabrication of EN devices.

Reference : Ramgir, Niranjan S. "Electronic nose based on nanomaterials: Issues, challenges, and prospects." ISRN Nanomaterials 2013 (2013).

Going without a Jerk

This article is a republished version of the Technical Article Board at SSET

Abstract

Potholes on the road are a great threat to motorists using the highway. Currently there is very little infrastructure to locate these and repair them in a timely manner. This article presents a method to report the exact location of the portholes without any manual step. You just need to put a smartphone in your pocket.

Introduction

The article here discusses the use of the accelerometer in the phone for detecting the potholes and reporting them to the civil authorities through a database. The database can be used to locate the potholes on a map and take remedial measures quickly. The work explained here has been an extension of that developed in Nericell by Microsoft Research Bangalore. The Nericell gives a map view of the locations that and provides extension to accident detection due to abnormal braking.

Prelims of Accelerometer

The accelerometer is a device used in every smartphone and is capable of determining the acceleration along each perpendicular coordinates – X, Y and Z. The measurements are taken relative to the acceleration due to gravity, \(g (= 9.8 m/s^2).\) The directions are illustrated below. Using the X, Y components accelerometer can measure the abnormalities in the road plane. Along the Z direction, abnormalities due to level shifts can be detected- potholes or bumps for instance.

X, Y and Z directions of accelerometer

How It Works

It is possible to determine the following from the 3 reported acceleration graphs.

• Breaking Detection – accident reporting
• Pothole Detection
• Speed detection

If \(x\) is the distance, then \(\frac{dx}{dt}\) is the velocity, and \(\frac{d^2x}{dt^2}\) is the acceleration. If we look into the higher derivatives of \(x\), it is possible to detect the changes is acceleration corresponding to sudden changes in the accelerometer signal. It is possible to identify the sudden spiking of the signal along the \(x\) axis and translate it a jerk. Now the intensity of the jerk is dependent on the speed of the moving vehicle. At high speeds (ie > 25 kmph) , the jerk is prominent, while the jerk is less noticed for lower speeds (ie <25 kmph).

References

Mohan, Prashanth, Venkata N. Padmanabhan, and Ramachandran Ramjee. "Nericell: rich monitoring of road and traffic conditions using mobile smartphones." Proceedings of the 6th ACM conference on Embedded network sensor systems. ACM, 2008.