nano micro

8/10/2019 Nano Micro

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IIT Bombay

V. Ramgopal Rao

Centre of Excellence in Nanoelectronics,

Department of Electrical Engineering

Indian Institute of Technology (IIT) Bombay, Powai,Mumbai, India

http://www.ee.iitb.ac.in/~rrao

Email: [email protected]

Nano/Micro-Electro-Mechanical-Sensor Systems

MICRO/NANO TECHNOLOGIES - AAA

2

Micro/Nano-fabrication technologies ideally suited for India:Diverse Applications, high-tech, batch processing and low

cost per die

Nanotechnology sustained high levels of funding in focusedhigh technlogy areas with product/technology as a focus

Build Multi-disciplinary Research Teams

Available, Accessible and Affordable technologies
http://www.ee.iitb.ac.in/~rraomailto:[email protected]:[email protected]://www.ee.iitb.ac.in/~rrao


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more than half of Indias population is under the age of 25, and one million

people a month are expected to join the labour force over the next decade.

Technologies that help youth excel & acquire skills

Indias massive agricultural sector employs about 60% of the population, yet

accounts for only about 17% of total GDP

Use innovation/technology as a vehicle to improve productivity

healthcare a major concern, rural health infrastructure hardly existent

14 million persons are infected with TB in India and more than 300,000 deaths occur every

year; about 2 million cases of malaria are recorded every year, by 2015 close to 5 million

infected with AIDS; 17.1 million lives are claimed by cardiovascular diseases, with 82% of

deaths occurring in low- and middle-income countries like India. India is home to about 40

Million diabetic patients .

Add to this: 42% Indians live on $2 per day & 22 Million population pushed below poverty

line annually due to healthcare expenditure

Security- a major concern area for India EnergyBesides all other energy related areas, we need to also focus on

Energy Scavenging Technologies (Vibrations, microwave energy..)

>> Available, Accessible and Affordable technologies

3

IIT BombayV.R. Rao: [email protected] from NPSM, DIT, NPMASS, DST

Students/Post-docs:Seena,Nitin Kale, Manoj Joshi, Sheetal Patil, Prashanthi, AbhinavPrasad, Deepika Reddy, Dilip Agarwal, Sudip Nag, Naveen Kadayinti,Neena, Avil Fernandez, Sahir Gandhi, Gaurav Chatterjee, RashiNathawat , Yashwant, Sandeep Surya Goud, Mihir,

Faculty Collaborators:

S.Mukherji (Immobilization), Dept. of Bio-Sciences & Engg.D.K.Sharma (Instrumentation): Dept. of Electrical Engineering

Anilkumar (Surface coatings), Dept. of ChemistryM.Shojaei (ASIC Design); Dept. of Electrical EngineeringP.R.Apte (Fabrication): Dept. of Electrical EngineeringC.P.Rao (Calixerines): Dept of ChemistryM. Ravikanth (Porphyrins): Dept of ChemistryPrita Pant (Nano-indentation): Dept. of Metallurgy & Mat.Sci.V.R.Palkar (Multi-ferroics), Dept. of Electrical Engg.B. K. Chakravarthy (Prototype-development) Industrial Design Centre

Amit Agarwal (Micro-fluidics), Dept. of Mechanical Engineering

T.Kundu (photo-thermal), Dept of Physics

B. K. ChakravarthyIndustrial Design Centre, IIT Bombay


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IIT Bombay

IIT BombayCENIIT Bombay

A Rs. 300 Crore National Nano-fabrication Facility @ IIT Bombaycreated from funding by DeitY, other agencies and industries. Asimilar centre (CENSE) in operation at IISc Bangalore. Two newcentres being created at IIT Delhi & IIT Madras.


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IIT Bombay

CENIIT Bombay

IIT Bombay

CENIIT Bombay


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IIT Bombay

What is Nanotechnology ?

Engineering of materials at the

Nanoscale in order to achieve usefulfunctions

A place for every atom and every atom in its place

How small is a Nano-meter really? the length finger nails grow roughly in one second


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IIT Bombay

For example, 5 cubic centimeters about 1.7 cm per side ofmaterial divided 24 times will produce 1 nanometer cubes andspread in a single layer could cover a football field

Repeat 24 times

Nanoscale = High Ratio of Surface Area to Vol.

Source: Clayton Teague, NNI

M. Meyyappan, NASA Ames Res. Center

IIT Bombay

What really is Nanotechnology ? size dependence

At the nanometer scale, properties become size-dependent

Higher surface to volume ratio (sphere):

Surface to volume ratio- A 3 nm iron particle has 50% atoms on the surface

- A 10 nm particle 20% on the surface

- A 30 nm particle only 5% on the surfaceFor example,(1) Thermal propertiesmelting temperature(2) Mechanical propertiesadhesion, capillary forces(3) Optical propertiesabsorption and scattering of light(4) Electrical propertiestunneling current(5) Magnetic propertiessuperparamagnetic effect

New properties enable new applications

RR

R 1

3

4

43

2

Spherical iron nanocrystals

J. Phys. Chem. 1996,Vol. 100, p. 12142


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IIT Bombay

Adapted from Evolution scenario for III-V/Ge devices on Si platform through (Takagi et al., ICSICT, 2010pp.50-53, 2010)

More than Moore Era of CMOS Scaling

Spintronics,MolecularElectronicsEtc. s

V.Ramgopal Rao


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IIT Bombay

More than Moore Era in CMOS

M. B. Wolfgang et al., 2010, "More than Moore" White paper (Intel)

IIT Bombay


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IIT Bombay

An Ultra-sensitive Piezo-resistivePolymer Cantilever Technology

iSens: A point of care system for Cardiac Diagnostics

Explosive Detection/Other Environmental sensors

Technology Enablers for Web enabled Cardiacmonitoring

System-in-Package solutions

IIT Bombay



Explosive Detection

Technology Enablers for Web enabled Cardiacmonitoring



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IIT Bombay

iSens: A point of care system for Cardiac

Diagnostics Ischaemic heart disease is the leading cause of death globally. About

one-third of all the deaths in the world are attributed to cardiacproblems. (Lancet 2006; 367: 1747-1757).

57 million (80%) deaths were in low-income countries. (Circulation2001; 104: 2746-2753) , & (N Engl J Med 2004; 350 (24): 2438-2440).

Between 1990 and 2020, these diseases are expected to increase by120% for women and 137% for men in developing countries,compared with 30-60% in developed countries. (Circulation 2001; 104:2855-2864).

By 2010, 60% of the world's heart disease is expected to occur inIndia. (BMJ 2004; 328: 807-810).

South Asians have a high prevalence of risk factors, have Ischaemicheart disease at an earlier age than people in developed countries. (J

Am Coll Cardiol 2001; 38: 682-687, JAMA 2007; 297: 286-294).

IIT BombayV.R. Rao: [email protected]

iSens : Considerations

Inexpensive, smart, rugged sensors that can be used

outside laboratories.

Should be relevant to present ground realities in India.

Changing lifestyles have made South Asians susceptible

to cardiac dysfunctions such as Acute Myocardial

Infarction.

Damage to an area of heart muscle occurs due to

inadequate supply of oxygen to that area.

Diagnosis of AMI done through various clinical and

pathological tests (e.g. ECG, CPK-MB levels, Troponin I

& T levels, myoglobin, etc.).

40% lawsuits in USA for wrong AMI diagnosis


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Molecular Markers Enzymatic markers

Creatine kinase-Total (CK)

Creatine kinase MB (CK-MB)

Lactate dehydrogenase (LDH)

Aspartate aminotransferase (AST)

Glycogen phosphorylase isoenzyme BB (GPBB)

Protein molecules

Troponin

Myoglobin

FABP

Cell-free laddered DNA fragments


Molecular Markers: Issues

Concentration & change of concentrationacross individuals

Specificity

Temporal response

Ease of designing assay protocols

Protocol robustness

Of the marker for the dysfunction

Of the sensor for the marker

Of the sensor system, includingreagents


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IIT Bombay

Temporal Variations of Markers

A: early release of myoglobin or CKMB isoforms after AMI;

B: cardiac troponin after AMI; C: CK-MB after AMI;

D: cardiac troponin after unstable angina.

Time(hrs)

Trop.I(ng/ml)

CKMB(ng/ml)

Myo.(ng/ml)

Normal 0.02-.4 0 .1- 7 20-92

1 0.4 3 200

8 0.8 8 900

12 10.4 30 50

24 22 60 40

48 14 18 40

72 9.3 2 39

IIT Bombay

Heart-type fatty acid binding protein(hFABP)

European Journal of Cardio-thoracic Surgery 19 (2001) 859-864


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Conventional Approaches Sequential assays for enzymatic activity

Immunoassays: ELISA (Enzyme Linked ImmunoSorbant

Assay)

Radioimmunoassay

Immunoprecipitation

Chromatography (!) Electrophoresis for separating isomers

and then looking for activity (for lab(skilled labor, time consuming))


Our approach

Biosensor array based on microfabricatedsequential assay systems

General approach is to use affinity sensors

Use direct affinity sensors:

Affinity cantilevers

EIS capacitors

Conducting polymer devices


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IIT Bombay

A Review on Cantilever Sensors

Surface Stress Temperature changes Resonant Frequency

Anja Boisen et. al., Cantilever-like micromechanical sensors, IOP Rep. Prog. Phys.74 (2011) 036101 (30pp)

Surface stress changes detected of the order of 106N/m

Measure temperature changes down to 105KMass change estimations in the atto- to zepto-gram (1021 g) Silicon based materials, Reliability & Optical Detection

IIT Bombay

In 1909, Stoney developed a theory to measure surfacestress/elastic strain of a thin film deposited onto a sheet ofmetal. Modified Stoneysformula:

Fundamental understanding still lacking on the origin of surface stress

compressivetensile

Anja Boisen et. al., Cantilever-like micromechanical sensors, IOP Rep. Prog. Phys.

74 (2011) 036101 (30pp)


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IIT Bombay

Bimetallic Cantilever tip deflection:

Resonant Frequency Changes

IIT Bombay

iSens Functional Architecture

Reagent

Input Filter

ReactorBiosensor

Array

Sample

SignalConditioning

+

Display

Control + ProcessingElectronics

Disposable part


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IIT Bombay

Polymer Microcantilevers

Polymer considered : SU-8

Et

L2

2 13nt ZDisplaceme

Advantages of SU-8

Lower Young's modulus (40 X lower compared toSi based materials!)

Inexpensive fabrication process & Ease in patterning

Compatibility for integrating sensor with CMOS & other micro fluidic components

Relatively stress free nature of the deposited film.

Schematic of microcantilever sensor

(5 GPa)

M. Joshi et al., IEEE/ASME Journal of Microelectromechanical Systems (J-MEMS), Vol. 20, No. 3, June 2011

N.Kale et al., (IEEE/ASME) Journal of Microelectromechanical Systems (J-MEMS), Dec. 2006

IIT Bombay

Polymer Microcantilevers -Piezoresistivetransduction

ysensitivit

E

K

4

R

Rs

EhK

Piezoresistive layers

Gold Poly SiliconSU-8/nanoparticle (ornanowire) Composites

OFET/TFTEmbeddedCantilevers-strain gauge.

-K 2.-Easy toincorporate.

- Lowersensitivity.

-Piezoresistive-K > 20 (dependent

on materialoptimization)

-Low Temperaturedeposition methodslike HWCVD.

- Stiffness increase- Smaller SNR

-Piezoresistive-K 90-Spin coatable- Compatible with

SU-8- Does not affect the

overall stiffness- Good sensitivity- Suffers from

Reproducibility

-Piezoresistive- K>200- Spin coatable- Lower stiffness- Good Sensitivity- Betterhomogeniety

IEEE J-MEMS, 2009

IIT Bombay Nanotechnology, 2011IIT Bombay

IEEE J-MEMS, 2011

IIT Bombay

J. Thaysen et al.,IEEE MEMS Conference

2002.


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SU8/Poly-Si/SU8 Cantilevers for detecting

Myoglobin

R/R (K/E) (4ss t ) Low Youngs Modulus E(5 GPa) of SU-8 High Gauge Factor K(20) of polysilicon SU-8 processing: simple and low cost Immobilization on SU-8: Surface

modification by novel ammonia crackingprocess (patented process)N.Kale et al., (IEEE/ASME) Journal of Microelectromechanical Systems (J-MEMS), Dec. 2006

M.Joshi et al., Journal of Micromechanics and Microengineering Dec 2010M.Joshi et al., (IEEE/ASME) Journal of Microelectromechanical Systems (J-MEMS), , June

2011

IIT Bombay

Hot-Wire CVD Cluster Tool for Low-Temperaturepoly/nitride Deposition

B2H6H2/NH3

Reactor

Gate Valve

Slit

Valve

Filament

Assembly

Gas

ManifoldMFC

LLTC

View Port

Shaft

Exhaust

line

Pirani Gauge

Nitin S. Kale et al., (IEEE/ASME) Journal of Microelectromechanical Systems (J-MEMS), Volume

18, Feb. 2009


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HWCVD Polysilicon as aPiezoresistor

Gauge Factor defined as

G.F.=(R/Ro)/

High gauge factor of polysilicon (K~30) as compared to that ofmetal (K~2)

Gauge factor of polysilicon depends on

Grain size

Doping concentration

Doping type Texture

Above factors dependent upon hot-wire process parameters likesubstrate temperature, hydrogen dilution and boron flow

IIT Bombay

Hotwire CVD Polysilicon asPiezo

Calibration for glass substrateHWCVD poly conductivityas a function of temp


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IIT Bombay

Low-temp HWCVD piezo-poly for SU8/nitrideCantilevers

Experimental

Experimental

Experimental

G.F.=(R/Ro)/

N.Kale et al., Proc. of the 8th IEEE Conference on Nanotechnology (IEEE NANO 2008),August 18-21, 2008, USA

IIT Bombay

Crystallinity (intensity of peak) increases with polysilicon film

thickness.

Grain size determined fromX-ray data, using Scherrers

formula

HWCVD Films for PolymerBio-MEMS


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IIT Bombay

HWCVD Films for Polymer Bio-

MEMS

GlassRMSroughnes: 1.8 nm

SU-8 on

glassRMSroughnes:0.58 nmHWCVD films deposited on SU-8/Glass show a

clear peak while the ones on glass show ahigh amorphous content

IIT Bombay

HWCVD Film Optimization

XRD of polysilicon filmsdeposited on SU-8 coated

silicon substrate with different

hydrogen dilution

Variation of gauge factor and grain sizefor polysilicon films deposited on SU-8coated glass and bare glass substratewith different hydrogen dilution


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IIT Bombay

Low-temp HWCVD piezo-poly for SU8/nitrideCantilevers

Experimental

Experimental

Experimental

G.F.=(R/Ro)/

N.Kale et al., Proc. of the 8th IEEE Conference on Nanotechnology (IEEE NANO 2008),August 18-21, 2008, USA

IIT Bombay

SU8-Polysilicon-SU8 Process Flow &Characterization

M. Joshi et al., Journal of Micromechanics and Microengineering, vol. 20 (2010) 125007.

Nitin S. Kale et al., (IEEE/ASME) J-MEMS, Vol. 18, Feb. 2009


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Polymer Cantilevers with embedded Carbon Blackparticles

CB/Polymer composite conducts for CBconcentration above percolation threshold

Conduction due to tunneling between twoaggregates : R/R due to change intunnel distance upon application of strain

Expected to be highly sensitive

Appl. Phys. Lett. 88, 113508 (2006); L.Gammelgaard,P. A. Rasmussen et al., TU Denmark


Variability issues with Polymer Nano-composites


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IIT Bombay

SU-8/Carbon Black Composite Nano-indentation Characterization

Schematic of load displacement curve

Oliver Pharr method to extract H and E

Scanned images of a set of Berkovich indent at the SU-8 surface

Load Vs indentation depth for different loads

Polymer Nano particle composite

IIT Bombay

SU-8/Carbon Black Composite :Characterization

1. Parallel mixing model: 2. Guth-Smallwood equation for modulus

Youngs Modulus of the composite as a function

of CB vol %Hardness of composite as a function of CB vol %.

Polymer Nano particle composite

Seena et al., Nanotechnology , 22 (2011) 295501


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IIT Bombay

Parameter Value

Cantilever

length

250m

Width 120m

Upper SU-8

thicknes

s

400nm

Lower SU-8

thicknes

s

1.8m

Die area 3.4mmX

1.5mm

SU-8 cantilevers with embedded Carbon Black Nano

particles

Fabrication of the devices IIT Bombay 6 mask process

Thinnest polymercantilevers withembedded Nano-particles

Seena.V. et al., Pro. of the 5 th International Workshop on NanomechanicalCantilever Sensors, May 19 - 21, 2008,Mainz, Germany 2008

IIT Bombay

Highly sensitive self standing SU-8cantilevers with embedded CB

Seena V. et al., Solid State Sciences (Elsevier), Volume 11, Issue 9, September 2009


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IIT Bombay

Electromechanical Characterization of SU-8 cantilevers with

embedded CB composite

These cantilevers are expected to

provide R/R of 10s of ppm for atypical antibody-antigen interaction[5mN/m]

Parameter SU-8/CB/SU-8

cantilever

SU-8/Au/SU-8

cantilever

Deflection

sensitivity

[ppm]

1.1/nm 0.3/nm

Surface stress

sensitivity

[N/m]-1

7.6*10-3 1.3*10-2

Surface stress sensitivity: ~8 ppm/ (mN /mt)Resonant frequency: 22 KHzSpring constant: 0.4 N/mt

IIT Bombay

Noise in Polymer Composite Cantilevers

Higher noise levels compared to SU8-Au-SU8.

Estimated minimum detectable surface stress ~ 39 mN/m


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ZnO Nanowire Embedded Strain Sensing

Cantilever

(a) Silicon dioxide grown on a silicon wafer (b) First encapsulation layer of SU-8 (c)Patterned Cr/Au layer for contact. (d) Pattering of ZnO seed layer (e) VerticalGrowth of ZnO Nanowire (f) Bottom encapsulation layer of SU-8. (g) Pattering ofSU-8 anchor layer.

IIT Bombay

LowYoungs modulus of polymer and the high strain sensitivity ofZnOnanowires, resulting out of the high surface area

Vertical ZnO nanowire grown using a low temperature (95 C) solutionbased hydro-thermal method.

Measured Surface stress sensitivity: 128 ppm/nm. Resonant Frquency: 30.4 KHz

Prasenjit Ray, V. Ramgopal Rao, ZnO Nanowire Embedded Strain Sensing Cantilever: A New

ultra-sensitive Technology Platform, To be published in J-MEMS, 2013


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IIT Bombay

Polymer Microcantilevers -Piezoresistivetransduction

ysensitivit

E

K

4

R

Rs

EhK

Piezoresistive layers

Gold Poly SiliconSU-8/nanoparticle (or nanowire)

CompositesOFET/TFTEmbeddedCantilevers-strain gauge.

-K 2.-Easy to

incorporate.- Lowersensitivity.

-Piezoresistive-K > 20 (dependent

on materialoptimization)

-Low Temperaturedeposition methodslike HWCVD.

- Stiffness increase- Smaller SNR

-Piezoresistive-K 90-Spin coatable

- Compatible withSU-8

- Does not affect theoverall stiffness

- Good sensitivity- Suffers from

Reproducibility

-Piezoresistive- K>100

- Spin coatable- Lower stiffness- Good Sensitivity- Betterhomogeniety

IEEE J-MEMS, 2009IIT Bombay Nanotechnology, 2011

IIT Bombay

IEEE J-MEMS, 2011IIT Bombay

J. Thaysen et al.,IEEE MEMS Conference

2002.

IIT Bombay

Pentacene or ZnO

Organic Transistor/TFT as a Strain Amplifier


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65

Polymer microcantilever with integrated OFET[B] Design and Fabrication of CantiFET

(A) Planar and (B) Cross sectional schematic of CantiFET device

Layer No Material Thickness

1. Cantilever first layer SU-8 1 m

2. Gate Cr/Au 5nm/ 80 nm

3. Gate Dielectric SU-8 900 nm

4. Source/ Drain Cr/Au 5nm/ 80 nm

5 .Organic semiconductor Pentacene 40-50 nm

Geometrical details of CantiFET

Layer details of CantiFET

Parameter Value

1. Cantilever length 340 m

2. Cantilever width 170 m

3. Cantilever overall thickness 1.9 m

4. Die area 4 mm X 4 mm

G

S

D

Reference andmeasurement

cantilevers

Structural SU-8

Gate Dielectric SU-8

Gate

Drain SourcePentacene

(A)

(B)

IIT Bombay

66


Device designsObjective : To understand the anisotropic nature of strain sensitivityof pentaceneCurrent direction parallel to strain Current direction both parallel and perpendicular to

strain

Current direction perpendicular to strain Current direction at 450angle to the strain

A

B

C

D


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Process flowConceptSource, drain and gatecontact pads open ontop side through OFETon the bottom side

Sacrificial layer SU-8 2002 structural layer Contact Pad and Gateelectrode of Cr/Au Gate dielectric

Source Drain contact of Cr/Au Thick SU8 pattering as anchor layer

Release of the devicefrom the silicon

IIT Bombay

Organic CantiFETs realized at IIT Bombay

V.Seena et al., IEEE/ASME Journal of MEMS (J-MEMS) , April 2012


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Polymer microcantilever with an integrated OFET

CantiFET Deflection Characterization

IIT Bombay

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Polymer microcantilever with integrated OFET[Characterization of CantiFET

L : Beam lengthLp : length of strain sensitive layerZnr : distance of strain sensitive

layer from neutral axisZ : the vertical deflectionk : the stiffness of the cantilever given by,

E :YoungsmodulusI : the moment of inertia.

12

pnr

LL Z k Z

L

EI

3

3EIk

L

3

3

4

h Z

L

Average strain , onpentacene layerin a rectangular microcantilever,

For CantiFET structure,Lp = L, and Znr = h (thickness ofcantilever)

The sensitivity, [(I/I)/nm]:15.6 ppm for 1 nm of deflection.

V.Seena et al., IEEE/ASME Journal of MEMS (J-MEMS) , April 2012


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IIT Bombay

71

Polymer microcantilever with integrated OFETCharacterization of CantiFET

Noise spectral density showed a 1/f1.72dependenceDrain current noise level at Vgs= Vds = -5V : 0.64 pA/Hz

1/f noise characterization

Min. surface stress sensitivity: 0.17 mN/m

IIT Bombay

Al- Doped ZnO thin-film transistor embedded micro-cantileveras a piezoresistive sensor

(a) Sacrificial layer (b) SU-8 2002 structural layer (c) Contact Pad andGate electrode of Cr/Au (d) Gate dielectric (e) Source Drain contact ofCr/Au (f) Thick SU8 pattering as anchor layer (g) Release of the devicefrom the silicon wafer RF sputter deposit a 50 nm AZO thin film


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Cantilever Platform: Low cost, HighlySensitive, Field Deployable

Bio-functionalization

System Level Integration

Cantilever Systems for

Cardiac Diagnostics

IIT Bombay

Selective ImmobilizationSurfaceTreatment

Immobilization chamber


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SU-8 chemical structure: Effect of Ammonia Treatment inHWCVD

(a) before ammonia treatment (b) after treatment

By cleaving the CO bond of the epoxy group, an amino group canget attached to one of the carbon atoms (verified with XPS)

M.Joshi et al., Biosensors and Bioelectronics, vol. 22, no.11,pp. 2429-2435, May 2007

IIT Bombay

Antibody Immobilization on Silicon Nitride and SU-8

Cantilevers (Dry)

Surface modification:Top surface of silicon nitride and SU-8

cantilever modified in Hot Wire CVD setup (Dry)

Linker attachment-Dip in 1% aqueous solution of homo-bifunctional

agent (glutaraldehyde) for 30 minutes

Antibody immobilization-Incubation of Human Immunoglobulin(HIgG) for one hour

Blocking of non-specific binding sites-Blocking of unsaturated

aldehyde sites and non-specific adsorption sites by dipping in BSA for

one hour

Identification of grafted antibody layer-Incubation of FITC taggedgoat anti HIgG for 1 hour


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Process steps in Silanization and Antibody Immobilization onSiO2surface

IIT Bombay

Steps in Antibody Immobilization

Silanization(grafting of silane layer)

Linker attachment (Glutaraldehyde)

Rinsing with PBS

Grafting Antibody Layer(HIgG/anti-Mb)

Rinsing with PBS**

BSA treatment **

Rinsing with PBS

Antigen (anti HIgG/Mb) binding

Rinsing with PBS

[HIgG]: 0.1 mg/ml; [anti-HIgG]: 0.05 mg/ml

[anti-Mb]: 0.5 mg/ml; [Mb]: 0.5 mg/ml


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IIT Bombay

ANTIBODY IMMOBILIZATION RESULTS

a)

b)

Micrograph of silanized surfacepatterned on silicon and treated withHIgG followed by FITC tagged goatanti-HIgG

SiO2

a) Micrograph of silanized SU-8 cantilevertreated with HIgG followed by FITC taggedgoat anti-HIgGb) Unmodified SU-8 surface showing selffluroscence property

SU-8

Si3N4

IIT Bombay

SU-8/Carbon black/ SU-8 cantilevers

Before Antibody Immobilization After Antibody Immobilization


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Antibody Immobilized SU-8/SiN-poly-SiN Cantilevers

Using Dry silanization protocol involving HWCVD

SU-8 with immobilization after theHWCVD surface treatment

Fluorescence microscope images of FITC tagged antiHIgGantibodies immobilized on a nitride/poly/nitride cantileverbio-functionalized by the process of dissociated ammoniatreatment

M. Joshi et al., Applied Surface Science, Vol.253,No.6, pp.3127-3132, January, 2007


Cantilever Systems

Cantilever Platform: Low cost, Highly

Sensitive, Field Deployable




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Cantilever Systems

Cantilever Platform: Low cost, HighlySensitive, Field Deployable



IIT Bombay

create a reaction chamberenvironment for cantileversensors such that sensing

time and SNR can bereduced along with theminiaturization of overallsystem.

we have developed a liquidcell for oxide/poly/nitrideand SU-8 cantilevers: usingPDMS

Liquid Cell Module


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IIT Bombay

Fabrication Flow of PDMS

Liquid Cell

IIT Bombay

PDMS Liquid CellSpecifications:

Base material: Poly-di-methyl-siloxane (PDMS)elastomer

Fabrication: Simple MEMSfabrication processes(optical Lithography,Plasma treatment, etc.)

Volume: 10-20 L

Advantages: Bio-compatible, easilypatternable, surface-modification easy,

transparent


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IIT Bombay

Key Features

Reliable R measurement down to 2ppm

Half/Full bridge configuration ofcantilevers

Compensation for R mismatch Precision performance Graphic LCD and in-built signal

generator (version 2) High resolution acquisition using 24-bit

ADC (version 2)

Adjustable gain and sensitivity Easy calibration Rechargeable battery operated system Low cost

Specifications:

Range of R: 40Kto 1MSensitivity: 0.7mV/ppmPower supply: 12V batteriesSupply current:


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IIT Bombay

The Best reported Cantilever CharacterizationTill date: IITB

IIT Bombay

Specifications of the CantileverCharacterization System

Range of R : 1K to 2M

Range ofR : 0.3 ppm to 2000 ppm

Sensitivity * : ~1.2mV/ppm

Resolution* : ~2ppm

Sampling Time : 0.25 seconds

Actuating signal : DC, 1.5V

Power Supply : +3V DC, 11mA (with RF)

PCB Size : 33mm 17mm 15mm

Neena et al.,Current Excitation Method for R Measurement in Piezo-Resistive Sensorsith a 0.3-ppm Resolution IEEE Transactions on Instrumentation & Measurement, March 2012

Neena et al. Piezoresistive 6-MNA Coated Microcantilevers with Signal Conditioning Circuits

for Electronic Nose Applications, ASSCC, 2012


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IIT Bombay

Bio-ICASPhoto of SC_IITB_2

IIT Bombay

Bio-ICAS, Recent Measurement Results of INA inSC_IITB_2

DC current=5.5 A Post-layoutsimulation

Measurement

Specification

Voltage Gain 19.98 dB 19.52dB

CMRR 115 dB 107dB

Input Diff. Voltage Range up to 40mV(pp)

up to 40mV (pp)

Input-referred voltage noisedensity (with chopper)

88nV/Hz at5Hz

50nV/Hz at5Hz

Input-referred voltage noisedensity (without chopper)

- 2V/Hz at 5Hz

Input common-mode voltagerange

0.6 to1.2V 0.7 to1.2V

Linearity (w.r.t. common-modeinput voltage)

- +/- 1.6%

Linearity (w.r.t. diff. input voltage) - +/- 1.5%

Optimal designfor ultra low-

power

consumption in

0.18 um CMOS

process.

At least 50%power reduction

maintaining high

CMRR and low

input noise,

compared to

latest reported

designs in higher

technology

nodes.


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Exploratory Sketches - iSens

IIT Bombay

CAD Packaging of Components


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A polymer composite cantilever based iSens Prototype

for cardiac Diagnostics

IIT Bombay

Ver-2 for Hospital Trials:

iSens Working prototype built jointly with NanoSniff Technologies Pvt. Ltd.


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Cantilever Characterization with antibody-

antigen interactions

Myoglobin

Detection

PBS

IIT Bombay

R Experiments ( RfRi )

MyoglobinAnti Myoglobin


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R Experiment using FABP Anti FABP

IIT Bombay

Only FABP ( No Anti - FABP )


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R Experiment using spiked serum ( with FABP )


Proposed Technology

iSens technology has the following pros &cons

Benefits: Simple procedure, low cost, fastresponse

Possible to integrate with CMOS technologies

Disadvantages: Unproven new technology

The system should be adaptable to newinternational standards for cardiac

diagnostics


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IIT Bombay



Explosive Detection

Technology Enables for Web enabled Cardiac

monitoring


IIT Bombay

Explosive Detection-Challenges ..1

Important factors for analysis and detection:

Specific Functional Group

Elemental Composition

Explosives under purview

TNT (2,4,6-TriNitroToluene)

RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine)

PETN (PentaErythritol TetraNitrate)


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Different Approaches: IIT-B

Introduction

The Challenges in Explosive Detection

Current Worldwide status

IIT-B Explosive Detection Approach based on

Cantilever Deflection

Deflagration (jointly with Prof. S.Mukherji, Bio-school, IIT-B)

Organic Sensors (OFETs)

Florescence Quenching Prof. Anil Kumar, Chemistry, IIT-B

Pattern Recognition

Surface Plasmon Resonance/ Evanescent wave based opticaldetection (Prof. S.Mukherji, Bio-school, IIT-B)

Orthogonality in package for reduced false positives

IIT Bombay

Cantilever based Explosive Detection @IIT Bombay

Surface coatings

(a) 4-mercaptobenzoic acid(4-MBA)

(b) Fluoroalcoholpolysiloxane polymer(SXFA)

(c) Porphyrincoating on cantilevers

(d) 6-Mercaptonicotinic Acid[6- MNA]

(e) Other proprietary coatings

Electrical Transduction


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MEMS Pre-concentrator

IIT Bombay

Microcantilever Experimental Setup for

explosive vapor detection

Schematic of the experimentalset up for explosive experiments

Experimental set up

Vapor generator with anMFC and 3 way valves forcontrolling Nitrogen andexplosive gases

Signal conditioningcircuit and a PTFE gasflow cell containingcantilever. Data acquisition

Vapor Generatordeveloped in TBRL


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Functionalization of Polymer Microcantileversfor Explosive Detection

Selective coating for Explosives

Sputtering of 5nm of Ti and30nm of Au.

Cantilevers are dipped in 6mMsolution of 4 -MBA* for 24 hours

4-MBA SXFA

SXFA in Chloroform is appliedselectively on the cantilevers

Cant#f (kHz) after Ti/AU

coatingf (kHz) after 4-MBA

1 100 79.5

Curvature of theCantilever after 4-MBAcoating

IIT Bombay1/31/2013

118

(3) Incorporation of smaller PTFE gas flow cell for microcantilevers

Polymer nanocomposite microcantilever sensor

Faster response with smaller flow cell (b) Effect of nitrogen flow rate

(a) (b)

10 mm diameter

PTFE flow cell

Nozzle:

2mm to 6mm

conversion


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IIT Bombay

Air Flush


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Piezo-resistive detection of explosives with

composite polymer microcantilevers

RDX & TNT: ppb level of detection routinely possible with thesemicro-cantilever systems now !

IIT Bombay

Flow rate from MFC

Temperature

Duration of dry

N2 purging beforestarting the

experiment

Functionalization


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Flow rate fromMFC

Temperature

Duration of dryN2 purgingbefore starting

the experimentFunctionalization

IIT Bombay

Flow rate from MFC

Temperature

Duration of dry

N2 purging beforestarting the

experiment

Functionalization


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Microcantilever Response to test samples

A: Benzophenone

B: Diphenyl Acetic Acid

C: TNT

D: Dihydrocholestrol

E: 3,4-Dimethoxy-2,5-

dimethyl ester of thiophene

F: diol diester of thiophene

G: m-Dinitrobenzene

H: 1-Chloro-2,4-

dinitrobenzene

I: 3,5-dinitrobenzoic acid

IIT Bombay

Microcantilever sensor for explosive vapor

detection

Experimental set up

Flow cell integrated with theCantilever PCB.

Vapor generator

Microcantilever PCB connected to asignal conditioning circuit

6 ppt of RDX on 4-MBA coatedcantilevers creates a surface stress ofroughly 30 mN/m

0.36 mV/ppb of TNT in ourpoly.comp. Cantilevershighest

reported


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Explosive Detector Prototype for RDX/TNT developed@ IIT Bombay

Seena et al., IOP Nanotechnology , 22 (2011) 295501

IIT Bombay


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E-Dog (s) to Sniff out Explosives

An ultra-sensitive

(parts-per-billion

level)

nano-electro-

mechanical

sensor

Wireless

TransmissionModule

A rechargeable

Li-Po battery

A real dogs nose 100 to 10 Million times more sensitive than humans. In

laboratory tests dogs were able to detect 1 to 2 parts billion routinely and in some

cases 500 parts per trillion, below the detection limit of any available equipment today.

IIT Bombay

Approaches to addressselectivity

Selectivity through coatings

Antibodies for explosives !! Cantilever Arrays

Orthogonality in package

Photo-thermal cantilever responsewith Pyroelectric materials



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Microcantilever sensor for explosive vapor

detectionExplosive detection- further approches

Use of dehumidification technique at the inlet of the sensor unit.

eg. A zeolite membrane Functionalizing microcantilevers using molecules having the Host-Guest

properties

1. Calixerines (A wide class of cyclic oligomers) Aromatic rings constitute cup shaped cavity. Deposited or immobilized onto solid surfaces. Inherit appropriate pre-organization of the host molecule,

since the calixarene macrocycle is shaped like a

conical basket, where it possesses a lower rimand an upper rim

2. Metallated Porphyrins Microcantilever arrays with different coatings on individual cantilevers and

perform a pattern recognition. Bringing orthogonality to sensing.

IIT Bombay

Miniaturized wireless explosive detector

PCBs for wireless explosive detector

Packaged flow cell for explosive detection

Fully automated and stand off detection

Packaging: CMET PUNEE


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IIT Bombay

Piezoelectric Cantilevers

Piezoelectric Photo-patternable PolymerComposites

- ZnO

- Various multiferroic materials

Multiferroic materials Mrunal A. K et al., "Electrical Actuation and Readout in a Nano-electro-mechanical Resonator

based on a Laterally Suspended Zinc Oxide Nanowire ", Nanotechnology, Vol. 23 (2012) 025501

Transduction applicationsEnergy Scavenging

Prashanthi et al., A Novel Photo-Plastic Piezoelectric Nanocomposite for MEMS Applications,IEEE/ASME Journal of MEMS(J-MEMS), April 2012

Prashanthi et al"Local piezoelectric response of ZnO nanoparticles embedded in aphotosensitive polymer", Physica Status Solidi RRL 6, No. 2, 77-79 (2012)

M. Kandpal et al., Photopatternable nano-composite (SU-8/ZnO) thin films for piezo-electric

applications, Appl. Phys. Lett. 101, 104102 (2012)

Self poweredwireless SensorNetworks


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ZnO-SU8 Polymer Composite Cantilevers forEnergy Scavenging applications

0 2 4 6 8 10

0

50

100

150

200

250

Piezoresponse(pm

)

Voltage (V)

(b)

Response recorded by placing thecantilever on a speaker

IIT Bombay

Coexistence of magnetic & ferroelectricordering in a certain range of temperature

Presence of coupling between two orderparameters (M-E effect)offers anadditional degree of freedom in devicedesigning

Tremendous application potential in thearea of MEMS and non-volatile memories

Development of Novel Multiferroic materialsfor MEMS Applications

Jointly with Prof. V.R.Palkar & Dr. Prashanthi K., IIT Bombay


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Material studies

1. Inducing ferromagnetism in antiferromagnetic BiFeO3without disturbing its

ferroelectricity by means of doping at Bi sites (Bi0.6La0.1Dy0.3FeO3)

2. Removal of La from Dy modified BFO system (bulk and thin films) leads to

reduction in the leakage current and improvement in ferroelectricproperties

enhancement in the magnetic properties by one order of magnitude

3. Magnetic anisotropy develops non-linearly with the thickness of the films

correlated to internal stress developed during growth process

4. Effect of permanent magnetic field and electric field on the dielectric

response of the BDFO thin films at GHz frequencies

The coupling between two phenomenon has been observed at

microwave frequencies

1. V.R.Palkar et al., Journal of Material Research, Vol.22, 2068-2073 (2007)

2. K Prashanthi et al., Solid State Communications,Vol.149, 188-191 (2009)

3. V.R.Palkar et al., Journal of Physics D: Applied Physics,Vol.41, 045003 (2008)4. V.R. Palkar et al., Journal of Material Research, Vol.22, 2179-2184 (2007)

IIT Bombay

Co-existence and coupling of Ferroelectricity andMagnetism at Macroscopic as well as at Microscopic Level

V. R. Palkar et al.,Applied Physics Letters,Vol. 93, 132906 (2008)

Coupling Between Ferroelectric andMagnetic Properties at Macro as well asMicroscopic Level

Very small magnetic-

field can inducelarge electric

polarization

We are not aware of a

prior observation of an

electric-field-induced

magnetic hysteresis in

the magnetic domain

structureCoexistance of Ferroelectricand Magnetic Properties atMacro as well as MicroscopicLevel


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BulkMicromachining

MEMS Devices Using a Novel Multiferroic BDFO System

Si wafer

Two-mask processwith contacts

Step 2: BDFO deposition byPLD

Step 3: Patterning of BDFOusing lithography and BDFOetching

Step 4: Etching of Si torelease the cantilever

IIT Bombay

Microfabrication Process for BDFO cantilevers with gold astop electrode

Step 1: RCA cleaned Siwafer

Step 2: Depositionof BDFO by PLD

Step 3: Patterning ofBDFO using lithography(mask1) followed byetching of BDFO in 5:1BHF

Step 4: Depositionof Cr/Au layers bysputtering

Step 5: Patterning ofCr/Au usinglithography (mask 2)followed by Au/Cretching

Step 6: Bulk etching ofsilicon using TMAH torelease the cantilevers

Silicon

Cr

BDFO

Gold

200-500um

40um


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IIT Bombay

IIT BombayDr. Prashanthi & Prof. Palkar


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Silicon Locket

Low power ASIC basedFabricated & working fine

Low cost SU8 AccelerometerMotion artifacts

Undergoing field trials in hospitals

TCS-Industry partner

Lead investigator: Prof. D.K.Sharma & colleagues from Bio-school


A miniaturized 3 channel 12 leadECG unit


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A modular 3 channel 12

lead ECG unit

Lead investigator: Prof. D.K.Sharma


ASIC for Silicon Locket


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Future Plans for SiLoc ASIC


Motion Artifacts


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First demonstration of polymer

based Accelerometer @IIT-B

Optical and SEM micrographs of a structure with a seismic masssupported by four beams attached to an anchoring region.

20m


Low cost polymer accelerometers forintegration with the ECG electrodes


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Polymer Composite Microaccelerometer

157

First time demonstration of Piezoresistive polymer MEMSaccelerometer.

Low temperature processing..

Simpler Process F low

Improvement in sensitivity due to the lower Youngs modulus

of structural Polymer.

Smarter designs aiming for any type of application or

performance improvement can be easily implemented due to

the micromachining potenti al of the polymer using standardUV lithography, e-beam l ithography, laser, X-Ray,

M icrosterioli thography etc.

IIT Bombay

Polymer Composite Microaccelerometer

Seena et al., Unpublished


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12 lead heart monitor with a

thermal printer

This is a portable ECG unit with a printer, which can be easilycarried by a doctor in a briefcase

The unit is battery operated.

It has a user interface with a pictorialguide for attachment for for any oneof the 12 standard ECG leads.

This allows a minimally trained personto take an ECG, which has obviousadvantages in a rural setting.

ECGs can be collected by a fieldoperator with printouts and thenexamined at the hospital by a doctor.


Realization of handheld Polymermicro-cantilever Sensor Systems

Polymer Cantilever technology highlysuitable for low-costdisposablehealth-care applications

The high sensitivity offered by this

technology helps build sensors forcardiac marker detection & fordetecting explosives in the vapor phasedown to the low ppt level

Simple instrumentation & low cost(piezo-resistive measurements) enabledevelopment of wire-less sensornetworks for environmental/ securityapplications

Low Temperature Processes (max 100deg C)Integration with CMOS -

Post processing for CMOS

Identify an application

Develop the technology

Product Realization

Commercialization


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Angel Funded by Priaas investments, R&D Funding by ICICISPREAD

16 people currently employed in NanoSniff including 5Ph.D.sThree Products: OmniCant TM , Explosive Detector, iSensOmniCant launched in August 2012Setting up of manufacturing facilities

[email protected]

IIT Bombay


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Technology Transfers from CEN, IIT Bombay

BeagleBigtech Industries, Bangalore (Prof. Anilkumar, Chemistry)

Surface Plasmon Resonance (Prof. S.Mukherji, DBSE)

A Detection system for E.coli and other waterborne bacteria (Prof. S.Mukherji, DBSE)

Ultra Low voltage Devices & High Voltage I/O Devices (Prof. V.Ramgopal Rao, EE)

Silicon Locket (Prof. D.K.Sharma, EE)

IIT Bombay

Prototypes/Products in the CEN@IIT-B

Explosive Detector

Silicon LocketPortable ECG Monitor

BEAGLE

Portable SPR System

PolySense Aqua

Explosive wireless sensor nod

A.Q.Contractor

S.Mukherji

Anilkumar

D.K.Sharma & team

D.K.Sharma & team


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Thank You

IIT Bombay

Approaches to addressselectivity

Selectivity through coatings

Antibodies for explosives !! Cantilever Arrays

Orthogonality in package

Photo-thermal cantilever responsewith Pyroelectric materials



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Adapted from Evolution scenario for III-V/Ge devices on Si platform through (Takagi et al., ICSICT, 2010pp.50-53, 2010)

More than Moore Era of CMOS Scaling

Spintronics,MolecularElectronicsEtc. s

IIT Bombay

Pentace/P3HT etc.


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Organic Transistor Platform for SensingApplications

A radiation study is carried out on OFETs tosee the effect of ionizing radiation

A P3HT based OFET is exposed to 60Coradiation (1 krad/min) for different time span

Change in the characteristics of the OFETs areobserved after each radiation dose

A control sample is also characterized at thesame time to see the effect of degradation inambient

(a) Radiation sensing

IIT Bombay

OFET Sensor Degradationwith Radiation

H. N. Raval, et al., Determining Ionizing Radiation using Sensors Based on Organic Semiconducting

Material, Applied Physics Letters, Feb 2009


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(b) OFETs for Explosive Detection

0 -10 -20 -30 -400

-1

-2

-3

-4

-5

-6

After Exposure

Before Exposureb

VGS

= 0 to -20 V

DrainCurrentID

S

(A)

Drain Voltage VDS

(V)

0 -10 -20 -30 -400

-2

-4

-6

-8

-10

-12

DrainCurrentID

S

(A)

Drain Voltage VDS

(V)

After Exposure

Before Exposure

VGS

= 0 to -20 V

a

R.S. Dudhe, et al.Appl. Phys. Lett., 93,2008, 263306

R.S.Dudhe, et al., Sensors andActuators A: Physical, Vol. 148, 2010,

pp.158.

Sandeep G. Surya et al.,, ",, Sensors &Actuators B: Chemical (Elsevier), 2012


OFET Passivation

Nitride passivation layers for polymer electronics

S.P. Tiwari et al., Organic FETs with Hot-wire CVD (HWCVD) Silicon Nitride as a Passivation and GateDielectric Layer, Volume 516, Issue 5, Pages 770-772, Thin Solid Films, 2008


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(c) OFETs for CO Sensing

To be published inAPL

IIT Bombay


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CO Sensing with Polymer Composite Cantilevers

IEEE Trans. On Nanotechnology , July 2012


Some Research Directions

Circuit Design for Energy Scavenging applications (Sub 0.3 V operation)

Device-circuit co-design (o/p resistance issues in piezo-electric MEMSdevices and its impact for circuit design) (series-parallel connection ofMEMS piezoelectric devices)

Low frequency Vibration Energy Harvesting (Devices, circuits, analysis)

Modeling polymer composite piezo-electric cantilevers/Size/shape effects

Asymmetric immobilization for Cantilevers

Novel piezo-resistive platforms Self powered ICs/Sensor systems

MEMS-CMOS co-design

MEMS-Organic electronics integration

Circuit design with organic electronics

OFET Sensors

Pattern recognition approaches/algorithms

Use of MEMS Switches to reduce CMOS Standby power/System levelmodeling

Sensors for Agricultural applications (Precision farming)

Ultra low power Micro-pumps for air & liquid handling (sensor networks)

Other cantilever based sensors


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IIT BombayV.R. Rao: [email protected] from NPSM, DIT, NPMASS, DST

Students/Post-docs:Seena, Nitin Kale, Manoj Joshi, Sheetal Patil,Prashanthi, Abhinav Prasad, Deepika Reddy, Dilip

Agarwal, Sudip Nag, Naveen Kadayinti, Neena,Avil Fernandez, Sahir Gandhi, Gaurav Chatterjee,

Faculty Collaborators:S.Mukherji (Immobilization), Dept. of Bio-Sciences & Engg.D.K.Sharma (Instrumentation): Dept. of Electrical Engineering

Anilkumar (Surface coatings), Dept. of ChemistryM.Shojaei (ASIC Design); Dept. of Electrical EngineeringP.R.Apte (Fabrication): Dept. of Electrical EngineeringC.P.Rao (Calixerines): Dept of ChemistryM. Ravikanth (Porphyrins): Dept of ChemistryPrita Pant (Nano-indentation): Dept. of Metallurgy & Mat.Sci.V.R.Palkar (Multi-ferroics), Dept. of Electrical Engg.B. K. Chakravarthy (Prototype-development) Industrial Design CentreAmit Agarwal (Micro-fluidics), Dept. of Mechanical EngineeringT.Kundu (photo-thermal), Dept of Physics

B. K. ChakravarthyIndustrial Design Centre, IIT Bombay

Initial Explosive Detector Prototypes

nano micro

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