Nanosciences @ I ndian I nstitute of Technology Kanpur Nano-Science - - PowerPoint PPT Presentation

Nanosciences @ I ndian I nstitute of Technology Kanpur

Nano-Science & Technology Initiative Department of Science and Technology, India Ashutosh Sharma Department of Chemical Engineering

DST Unit on Nanosciences @ IITK

Mesoscale Structures, Patterning and Properties with Emphasis on Soft Materials and Thin Films A state-of-the-art facility and resources for soft matter nanoscience and nanotechnology. Explore new techniques of nano-fabrication based

• n a creative combination of “top-down” including

soft lithography, self-assembly and self-

• rganization.

Projects related to nano-scale understanding, fabrication and use of soft materials in coatings, NEMS, functional interfaces and bulk-nano

Journey of the last two years!

Nano-Sciences at IITK: A Mega-Passion…….

Self-assembly

Micro- and Nano Fab tructure Property Behavior

Lithographies, Beams…

• p-
• wn

Bottom-up

Self-organization

Highly Multidisciplinary AND Interdisciplinary Team

CORE GROUP FACULTY (~ 10) Ashutosh Sharma (soft nano fabrication; nanomechanics) Ramesh C. Budhani (magnetic nanomaterials; spintronics)

• V. N. Kulkarni (ion beams; fabrication)

Department of Chemical Engineering Animangsu Ghatak (microfluidics; soft fabrication) Yogesh Joshi (polymer-clay nanocomposites) Nishith Verma (carbon nanocomposites) Jayant K. Singh (simulations of soft materials)

Department of Chemistry Sandeep Verma (self-assembly; nano-bio) Department of Materials and Metallurgical Engineering Ashish Garg (thin films; nano-structures) Department of Mechanical Engineering Shantanu Bhatacharya (nano-fabrication; MEMS) Department of Physics Rajiv Gupta (SPM; Raman) (Additional members may be co-opted depending on the focus of research---soft materials based patterning and their expertise in the Unit resources)

Major Facilities at Nanosciences Center

About 2500 sq. ft. of class 1000-100 clean rooms Fabrication resources Characterization resources Collaborations: Northwestern; UI UC; UCI ; Cambridge; NI ST; JNCASR; I I Sc……. Fall 2007

Fabrication

Focused Ion Beam (Dual Beam FIB) E-Beam Lithography Broad Beam Ion Mill Maskless Photolithography Pulse laser Coating Langmuir-Blodgett Deposition NSOM UV Lithography Nanoimprint Lithography Polymer Ink-jet Printing High temperature furnaces…..

Characterization

Confocal Microscopy Micro-Raman Scanning Probe Microscopies Near-field Scanning Optical Microscopy (NSOM) Imaging and Spectroscopic Ellipsometry Profilometers (Mechanical and Optical) SEM WAXRD; SAX SQUID Optical Microscopes Contact Angle Goniometer……..

Specific Scientific Objectives: Development of novel and facile techniques for patterning, structuring and fabrication using soft materials like polymers, gels, biological materials Development of functional interfaces such as super- hydrophobic surfaces and super adhesives based on meso patterning of surfaces Attachment –detachment energetics of sub-micron particles to surface and modulation by surfactants Synthesis of ordered arrays of quantum dots and nanowires including doped oxide and metal alloys and magnetic materials

Exploration of interfacial instabilities and failure mechanism in soft nano-structures Development of soft composites including polymer- nanoclay composites, thin film of meso-porous silica and its nano composites Magnetic nano particles and assemblies Development of computational nanomechanics Micro-SQUIDS and nanoscale magnetics including magnetic relaxation and supermagnetism Fabrication of carbon meso-structures based on soft fabrication techniques Microfluidic based devices and sensors

Current Areas of Nanosciences at IITK Fabrication using FIB, E-beam (masters; devices…) Novel soft-lithographies for large area, meso- patterning: “top-down” meets self-organization Nano- mechanics of soft confined materials Fabrication of novel MEMS: C-MEMS for micro- battery and cell-arrays Nanocomposites: polymer, carbon, clays, silica... Meso-textured Smart functional surfaces: superwetting; smart adhesives; optical and printing surfaces……

Interfacial/Colloidal interactions in aqueous media with polymer/surfactant adsorption Stability of soft nanostructures including structures produced by nanoimprint lithography Nanobiology: Scaffolds Nanoparticles, nanofibres and nanofilms: semiconductors, metals, polymers, carbon, ceramics, organics….. Nanostructured Magnetic Materials; spintronics

Nano-Patterning of Soft Materials In devices; MEMS/NEMS; Sensors; Smart Surfaces; Micro-fluidics; Super-capacitors and Batteries; Smart Adhesives; Functional Interfaces……….. 1.Facilities for large area, rapid patterning: Inkjet Printing, Gravure Printing, Nanoimprint Lithography, Laser Writing, FIB, E-beam……

• 2. Technology development for new patterning

methods based on self-assembly, including e-field assisted patterning, phase change, dewetting, phase separation and stress-engineering, Nanocoatings; Fast micro/nano Texturing…….

• 3. Products:

Smart and Functional Surfaces by Patterning: Adhesives, Anti-reflective Coatings, Structured Colors, Anti-fouling, Super-wetting Carbon patterning: MEMS, High Area Batteries Bio- and Chemical Sensors Fluidic Devices Opto-electronic Devices Difficult to fabricate Functional patterns

Additional Recent Nano-Grants: Self organized patterning of polymers, British Council (UKIERI), Rs. 2.4 millions (co-PI from UK: Prof. Ullrich Steiner, Cambridge University). Carbon MEMS, part of Indo-US Center for Advanced and Futuristic Manufacturing, Indo-US Science and Technology Forum, 2006-2008. Rs. 6.4 million (Coordinator: Prof. Amitabha Ghosh; US collaborator:

• Prof. Marc Madou, UCI).

Manufacturing Robust Nanostructures: Materials, Methods and Metrology, Indo-US Science and Technology Forum, Frontiers of Engineering (FOE) Award for collaboration with NIST Rs. 2.5 million. (US co-PI: Christopher Soles). Mesostructured Functional Thin Films and Interfaces of Soft Materials, Department of Science and Technology, 2007--2010. Rs. 49 million. Understanding adhesion of soft particles, Proctor & Gamble, 2008-2009. Rs.3 million

Some Innovations A novel micro/nano fluidic adhesive has been prepared and shown to be vastly more effective A novel nano fabrication method based on gel miniaturization has been proposed Three novel methods for self-organized sub-micron patterning of polymers on large areas have been developed and currently being further fine-tuned for applications. A novel highly asymmetric nano-porous silica surface has been synthesized. One face of this surface is super- hydrophobic and the other is hydrophilic. Potential applications are in textile and barrier coatings.

Application of electric fields to pattern the surfaces of soft visco-ealstic materails on sub-micron lengthscales by spatio-temporal variation of the e-field. A novel technique for synthesis of colloidal solution of nanoparticles has been developed. This pulsed laser based method allows synthesis of multicomponent oxide and metal alloy nanoparticles, which is rather difficult to achieve with the know methods. Stress tuning has been used to create novel 2- dimensional fractal networks of iron.

2006-07

Over 70 publications in International Journals 3 patents filed and 1 disclosure 14 PhD students and several project staff trained In addition to the Unit funding ~ 15 Carores, 6 additional nano related projects ~ 7 carores generated; two industry supported Collaborations with Cambridge, NIST, Lehigh, UIC, JNCASR, Saha Institute, TRDDC, NUS……….. Exciting new discoveries!!!!

Grand Challenges of Soft Patterning “Top-down” Meets Self-Organization!! Sub-micron Features on Large areas (> cm; beyond!) Rapid (m per second !! ); (roll-to-roll?; parallel) Integration across Different Materials (hydrogels, ceramics, carbon……) Process Complexity; Resources, Cost…. Patterning beyond Master: One Master, Many Slaves In-situ Tuning of Patterns Programmable Patterning

Functional Nano-structured Interfaces: Smart-adhesives

Producing High Strength Re-usable Soft Adhesives: Bio-inspired Adhesion

Examples of Bioadhesives

Adhesive pads of insects Setae of Gecko

Elastic Film

t

d h

F

G, J/m2

7 8 3 5 4 6 2 1 0.0 0.3 0.6 0.9 1.2 1.5 1.8 9 10

Microfluidic adhesive

(Majumder, Ghatak & Sharma; Science, 2007)

Fabricating in ‘Exotic’ Functional Materials: Carbon: Micro/ nano Webs and C-MEMS Energy: micro battery, micro-fuel cell, super capacitor…. Electronics: molecular switches, memory…… Biomaterials: C-MEMS……. Environment: Adsorption & catalytic media…

With Marc Madou, UCI

Difficult to Fabricate Functional Materials: Carbon

Energy: micro-fuel cell, micro battery, super capacitor….; Biomaterials……. Pyrolyzed Polymer structures !!

Stability : Stick Functionalization: Carbon fibres

Collaborator: Marc Madou, UCI

Nano-Imprinting Challenges: Uniform high pressure/temperature Conformal contact/Curved surfaces Stamp Removal Meeting the Challenges Flexible thin foil stamps Solvent vapor assisted softening of polymer films Spontaneous conformal contact by adhesive forces Soluble moulds/masters/stamps

Structural Colors by Micro-patterning: Adhesive Force

Lithography with Flexible Foils: Variety of Surfaces and Materials

PS polymer; 6 cm2 Hydrogel Sharma et al., Macromolecules 2006 Almost any polymer on any surface!! Curved

Patterning Beyond Master : Pattern Miniaturization 400 nm structures starting from 800 nm master

Sharma et al.

Patterning by Elastic Contact Instability: A New Micro/Nano Fabrication Tool

pattern length scale ~ 3 H

• A. Positive

Replica

• B. 2-D

Bifurcation

• C. Compress:

Negative replica

• D. Pull
• E. Feature size

reduction: Thin film W ~ 2L Sharma et al. Langmuir 2006

Patterning by Electric Fields: A New Fabrication Tool

Sharma, Shenoy, Narayan et al., Adv Mat 2006

Controlled Self-organized Dewetting: A New Fabrication Tool Sharma et al.

Robust Nanoimprint Lithography

Sharma & Soles (NIST)

• 1. Imprinting of soft elastic films
• 2. Imprinting of viscous polymeric liquid films

ISSUES:

A.Stress, strain, flow and structure relationships B.

• B. Stability and fidelity of imprinted structures

Stability and fidelity of imprinted structures C.

• C. Metrology

Metrology

m o ld (S i, Q u a rtz ) im p rin t m a te ria l s u b s tra te re le a s e R IE e tc h im p rin t (fo rc e ,U V , h e a t) m o ld (S i, Q u a rtz ) im p rin t m a te ria l s u b s tra te re le a s e R IE e tc h im p rin t (fo rc e ,U V , h e a t)

Nano-Patterning of Surfaces by Self-assembly: Sandeep Verma

a b

Adenine- Silver Metallaquartet HOPG

• J. Am. Chem. Soc. 2006, 128, 400-401

Adenine- Silver Duplex HOPG

a b

• J. Am. Chem. Soc. 2007, 129, 3488-3489

• J. Am. Chem. Soc. 2006, 128, 400-401

a b

a b

• J. Am. Chem. Soc. 2007, 129, 3488-3489

Sandeep Verma, Chemistry

Peptide morphologies

FFPP PPFF PFFP

• J. Pep. Sci. 2007, 14, 118-126
• Chem. Eur. J. 2008,

14, 1415-1419

• Angew. Chem. 2008,

47, 2217-2221

• Angew. Chem. 2008,

47, 2860-2863

Laser Ablation Assisted Growth of Quantum Dots & Quantum Wires and Their Magnetic Properties Ag colloid in aqueous SDS (R. Budhani et al.)

10 20 30 40 10 20 30 Counts Diameter (nm)

(b)

50 nm 50 nm

(a) (b)

• 60 -30

30 60

• 600

600

Applied field (kOe)

Perpendicular In-plane

(f)

M (emu/cc)

• 600

600

T G = 750

0C

M (emu/cc)

(e)

• 600

600

• 60 -30

30 60

T G = 700

0C

M (emu/cc)

(d)

TG = 700

0C

TG = 750

0C

TG = 800

0C

(a) (b) (c)

2.0 μm 2.0 μm 2.0 μm

SEM images and Perpendicular magnetization loops of 50 nm CoPt thin films deposited at various substrate temperatures at a growth rate of 0.4 Å/sec on single crystal STO (001). All the samples were post annealed for 25 minutes. Magnetization panel for the sample grown 800 0C also shows data for in-plane configuration. CoPt Fractals and Nano dots Budhani, Rakshit et al.

• Appl. Phys. Lett. 02511 (2006)

Fabrication using FIB

• 1. 2-D Patterning (masks, molds, stamps)
• 2. 3-D Structures (AFM tips, cantilevers,

devices)

Focused I on Beam: Nanomachining and Beyond

Sample (mounted on a precision Ion Beam (Ga+ 3-30 KeV) Spot size 7 nm Scan Generator for SEM Scan Genera tor for FIB Monit

• r

SE D/ SI D

N N NOVA

OVA OVA N

N NANO

ANO ANOL

L LAB

AB AB

Nova NanoLab Nova NanoLab

Nano- Milling Deposition

Micro Squid with Nb

Films; Anjan Gupta et al.

EXAMPLES

Holes (100 nm dia.) drilled in NbSe2 for patterning the

magnetic vortex states; Satyajit Banerjee et al.

Platinum electrodes separation 50 nm; I-V characteristics; Child Langmuir law at nanometer scales;

• S. Bhattacharjee

Superconducting Nano-Devices

• 0.3
• 0.2
• 0.1

0.0 0.1 0.2 0.3

• 4
• 2

2 4

• 0.3
• 0.2
• 0.1

• 20

dV/dI in ohm Current in mA PLOT of dV/dI vs I

voltage in mV Current in mA

V-I CHARACTERISTIC of Nb JJ

IC ~ 80 µA

(180(L) x 170(w) x 80(t) nm3)

• 0.4
• 0.2

0.0 0.2 0.4

• 4
• 2

2 4

Voltage in mV C urrent in m A

V

• I C

haracteristic of N b S Q U ID (H =0)

• 0.4
• 0.2

0.0 0.2 0.4 10 20 30 40

dV/dI in ohm C urrent in m A

SQUID Loop Area: (3.3 x 3.3) μm2 JJs:: 200(L) x 180(w) nm2

Maskless optical lithography + FIB milling; A. Gupta et al.

Carbon Cantilevers and Particles on AFM Tip Kulkarni et al. Sharma et al. AFM measurements of force-distance require dense spherical carbon particles 2-5 micron attached to the AFM tip

AFM Tips for Nanoindentation AFM tip of well defined shapes are required; grown Tungsten tips of hemispherical shape with the required end radius of 50 nm Sharma, Kar, Deva et al.

50 100 150 200 250 300 350 400 450 500

• 20

20 40 60 80 100 120 140 160

(z

1,s 1)

s [piezo displacement, nm] z [diflection, nm ] z =(z

1-z 2)

s = (s

2-s 1)

h = (z-s) (z

2,s 2)

tip m

• vem

ent range of analysis

Fig 2. Vertical displacement

0.2 0.4 0.6 0.8 1.0 50 100 150 200 250 300 350 400

Elastic modulus [MPa] h [indentation depth, nm]

• Fig. 3 Modulus vs indentation depth

Meso-patterning of thin polymer films by atomic force microscope assisted electrohydrodynamic nanolithography

Xie, Chung, Bandyopadhyay, Sharma, et al,

• J. Applied Phys. 103, 024307 (2008).

selected paper in Virtual Journal of Nanoscale Science & Technology, 17 (5), 2008.

0th1st2nd

Fabrication of Small Things: Top-Down Bottom-up Self-organization

Miniaturization

Ghatak, Sharma et al. Adv Mat (2007)

2006-07

Over 70 publications in International Journals 3 patents filed and 1 disclosure 14 PhD students and several project staff trained In addition to the Unit funding ~ 15 Carores, 6 additional nano related projects ~ 7 carores generated Collaborations with Cambridge, NIST, Lehigh, UIC, JNCASR, Saha Institute, TRDDC, NUS……….. Exciting new discoveries!!!!

Best way to predict the future is to invent it….