Individual projectIndividual project

NanomaterialsNanomaterials

HIGH SENSITIVITY SENSORSHIGH SENSITIVITY SENSORS

Student:

Cenan Marius Paul

Teacher:

Cristina Felea

INTROINTRODUCTIONDUCTION

Oxford English Dictionary defines the Oxford English Dictionary defines the sensor as “a device that detects and sensor as “a device that detects and records the conditions or properties, records the conditions or properties, indicate or sometimes respond to indicate or sometimes respond to information received”information received”

Features:Features:

use areause arearesolution (sensitivity)resolution (sensitivity)maximum stimulus frequency that can be maximum stimulus frequency that can be detected (selectivity)detected (selectivity)accuracy (measurement error)accuracy (measurement error)sensor size and weightsensor size and weightoperating temperature and environmental operating temperature and environmental conditionsconditionslifelifelong-term stability and costlong-term stability and cost

Use to measurement of:Use to measurement of:

pressurepressuredistancedistancemovementsmovementsspeedspeedaccelerationaccelerationforceforcetemperaturetemperaturechemical concentrationchemical concentration

by microstructural by microstructural changes such as reducing changes such as reducing the particle size to the particle size to nanodimensions (5-50 nm), nanodimensions (5-50 nm), which improves the which improves the properties and properties and performance of gas performance of gas sensors due to increased sensors due to increased surface area.surface area.

The sensor The sensor sensitivitysensitivity can be improved by can be improved by doping (changing the concentration) ordoping (changing the concentration) or

OXIDE SEMICONDUCTOR FILMS USED OXIDE SEMICONDUCTOR FILMS USED AS GAS SENSORS FOR AS GAS SENSORS FOR

ENVIRONMENTAL MONITORINGENVIRONMENTAL MONITORING

Conductive films used as gas sensors

Material Working temperature(ºC)

TiO2 700-1000

SrTiO3 700-1000

Ga2O3 900-1000

Nb2O3 700-1000

CeO2 700-1000

BaFeNb9O10 720

BaTi2Nb4O25 720

BaFe0.8Hf0.2O3 400-800

Material Working temperature (ºC)

SnO2 250-500

ZnO 400-500

TiO2 400-500

CeO2 400-600

Nb2O5 400

WO3 500

Ga2O3 550-600

Conductive materials used as gas sensors

Sensors based on oxide Sensors based on oxide materials materials (SMO)(SMO)

report, evaluate and monitor the presence report, evaluate and monitor the presence of gasof gas

chemical resistance and high temperature chemical resistance and high temperature field that can be usedfield that can be used

Network image of Tungsten Network image of Tungsten oxide nanowiresoxide nanowires

PRELIMINARY RESULTSPRELIMINARY RESULTS

WWe investigated the behavior of e investigated the behavior of several oxides andseveral oxides and

TiOTiO22 has been the most extensively has been the most extensively used in controlling air/fuel ratio in internal used in controlling air/fuel ratio in internal combustion enginescombustion engines. . This oxide can also This oxide can also be used in wastewater purification.be used in wastewater purification.

NANODOCTORS IN 30 YEARSNANODOCTORS IN 30 YEARS

to provide medicationto provide medication

tumor removerstumor removers

analysis and rebuild tissue destroyed by analysis and rebuild tissue destroyed by accidentaccident

A nanorobot, able to administer poison only target bacteriaA nanorobot, able to administer poison only target bacteria, , would would greatly simplify things, “said Ottilie Saxl, chief executive of the U.S. greatly simplify things, “said Ottilie Saxl, chief executive of the U.S. Institute for Nanotechnology”.Institute for Nanotechnology”.

REFERENCES:REFERENCES:

www.jnanobiotechnology.com/articleswww.jnanobiotechnology.com/articles www.chimie.go.rowww.chimie.go.ro www.disclose.tv/action/viewvideo/3062/www.disclose.tv/action/viewvideo/3062/Nanotechnology__Nokia_Morph_Concept_2008Nanotechnology__Nokia_Morph_Concept_2008 www.nanowerk.com/nanotechnology/research_news.phpwww.nanowerk.com/nanotechnology/research_news.php P. Tmoseley, J. O. W.Norris, D. E. Williams, Techniques and P. Tmoseley, J. O. W.Norris, D. E. Williams, Techniques and mechanisms in gas sensing, Adam Hilger, Bristol, 1991 mechanisms in gas sensing, Adam Hilger, Bristol, 1991 . E. Williams, P. T. Moseley, . E. Williams, P. T. Moseley, J. Mater. Chem.,J. Mater. Chem., 11, 809-825(1991) , 809-825(1991) M. Kuwabara, T. Ide, Co gas sensivity in porous semiconducting barium M. Kuwabara, T. Ide, Co gas sensivity in porous semiconducting barium titanate, titanate, Am. Ceramic Soc. BullAm. Ceramic Soc. Bull., ., 66,66, 1401-1405(1987) 1401-1405(1987) C. M. Chiu, Y. U. Chang, The structure, electrical and sensing properties C. M. Chiu, Y. U. Chang, The structure, electrical and sensing properties for CO of the La0.8Sr0.2CO1-xNixO3-for CO of the La0.8Sr0.2CO1-xNixO3- system, system, Mater. Sci. Eng. AMater. Sci. Eng. A, , 266266, 93-98(1999) , 93-98(1999)