Manipulation of Multiwall Nanotubes (MWNT) and Study of Frictional Interaction with Surfaces Dana Research Centre, NEU 11/10/2018

Points of Discussion Dana Research Centre, NEU Motivation to study Carbon Nanotube surface interaction How was it accomplished? Surfaces Analyzed Experimental Data Extraction Experimental and Theoretical Match Data Analysis Conclusion and Future Work Dana Research Centre, NEU 11/10/2018

Carbon Nanotubes (CNT’s) Arm Chair Structure Zigzag Structure Arm Chair  Metallic Nature Zigzag  Semiconducting Nature High Current Densities  1010 A/cm2 High Mechanical strength  Carbon bonding stronger than Diamond Z. Yao, et al Phys. Rev. Lett. 84, 2941 (2000) Dana Research Centre, NEU 11/10/2018

CNT Applications and Motivation SWNT electromechanical switches by CHN Switch Actuation leads to NT–SiO2 interface slip AFM used to Characterize the slip P Ryan et al, J. Micromech. Microeng. 21 (2011) 045028 NEMS Oscillators NEMS Memory Devices Metallic Nanotube, RTSET by AFM manipulation. NTs between Au electrodes on top of a Si/SiO2 substrate Strong bends act as tunnel barriers for electron transport AFM Manipulation is simple and effective AFM Manipulation is a reversible process Ch. Postma.et al, SCIENCE VOL 293 6 JULY 2001 RTSET = Room Temperature Single Electron Transistor; NT = Nanotubes; SWNT = Single Wall Nanotube , CHN = Center for High Rate Nanomanufacturing NEMS = Nanoelectromechanical Systems ; AFM = Atomic Force Microscopy Dana Research Centre, NEU 11/10/2018

CNT Interaction with Surfaces   Straightening the tube Bending the tube AFM controls the shape and position of individual MWNT dispersed on a surface AFM can straighten, bend and under certain conditions cut nanotubes. AFM manipulations are feasible due to the interaction between nanotubes and the substrate Estimation of CNT Binding energy with the surface Tobias Hertel, et al. J. Phys. Chem. B, Vol. 102, No. 6, 1998  Cutting the tube Dana Research Centre, NEU 11/10/2018

AFM as Nanomanipulation Tool SEM Image of AFM Cantilever Si N-type Cantilever Cantilever Stiffness = 2 N/m Frequency = 70 kHz; Tip Radius < 10 nm; AFM System Accessories Acoustic Enclosure Active Vibration Table Control Commands and Data Acquisition Scan area display Control Electronics AFM System Optical Microscope Laser Alignment XY Scanner Z Scanner Scan Head PSIA XE-150 AFM at CHN, NEU First to introduce Cross talk elimination in the XE series Dana Research Centre, NEU 11/10/2018

Theoretical Modeling Dana Research Centre, NEU 11/10/2018 Final CNT Deformed shape Case A (load 50% length) Case B (At 40% Length) Case C (30% Length) Modeling based on equilibrium bent elastic rod equation Equation realized in MATLAB to generate range of shear stress curves E = Young’s Modulus I = Second Moment of C/s area; D = Diameter of the tube b = Effective Contact width with the surface; α = 0.05D Palaniappan Nagappan , Journal of Tribology, JULY 2009, Vol. 131 Dana Research Centre, NEU 11/10/2018

Previous Manipulation Work Original CNT Manipulated CNT Small Aspect Ratio tubes (Length / Diameter) Lesser degree of deformation Manipulation Vector Position away from CNT mid point Curve fitting based on eye coordination Parameter ‘α’ taken as 0.6 arbitrary Only SiO2 surface manipulation VIDYARANYA RAMPURKAR, NEU 2009 Experimental and Theoretical Curve Fitting Dana Research Centre, NEU 11/10/2018

Estimation of Shear Stress Numerical Calculation for Estimation of Shear Stress CNT Structural Parameters, Diameter (D) and Length (L) of nanotube extracted from AFM Imaging tool (XEI) Aspect Ratio (A) = Length/ Diameter Effective contact width (B) Elastic Young’s Modulus (E) = 1Tpa Cross-sectional moment of Inertia (I), I = Π/64 (D4) Dimensionless shear stress (τ), Determined from the Range of curves Shear Stress (Mpa) Dana Research Centre, NEU 11/10/2018

CNT Selection and Solution Preparation CNT’s selected are near perfect straight ones Wide Range of Aspect ratio Nanotubes (80<A<653) Production by Arc Discharge Method Production method yields High Percentage of impurities CNT Solution preparation with IPA and DMF for better solubility TEM images of (a) an arc-MWNT, (b) a CVD-MWNT. Salvetat JP et al, Adv Mater 1999;11(2):161–5 CNT Solution in DI water CNT Solution in IPA CNT Solution in DMF Dana Research Centre, NEU 11/10/2018

Manipulation Procedure Original CNT Imaged in the Non contact mode operation Desired Aspect Ratio (>80) CNT selected CNT is dragged according to the vector drawn in Contact Mode Operation Vector drawn very close to midpoint , long enough and normal to the CNT to achieve effective deformation shape After manipulation, Imaging done again in Non contact Mode Sometimes after manipulation imaging is done several times to locate the deformed CNT Collected AFM Images are processed by XEI software Mithun Chandrasekar, NEU 2012 Original CNT Manipulation Vector Manipulated CNT Dana Research Centre, NEU 11/10/2018

CNT Length Determination CNT Length: 3.9µm Dana Research Centre, NEU 11/10/2018

CNT Diameter Determination 3 Point Diameter Measurement  Better Accuracy, offset subtraction CNT Diameter: 16nm Dana Research Centre, NEU 11/10/2018

Experimental Curve Extraction Blue line is a benchmark of the manipulation vector Image contrast is increased for better curve tracing CNT deformed shape is traced with Microsoft curve drawing tool Dana Research Centre, NEU 11/10/2018

Experimental and Theoretical Fit Based on the Experimental curve extracted, appropriate range of MATLAB curves are generated Experimental curve with its vector (Blue line) is mapped to the theoretically generated MATLAB curves Vector as reference line is centered on the 0 x coordinate to determine the deformed CNT shape value 0.48 represents the length ratio of the CNT, where the load is applied. Non uniform deformation, one side has curved more than the other. Curve around the drag point and one of the sides does provide sufficient fit. τ: 350 Increasing value of shear stress Experimental and Theoretical Fits Dana Research Centre, NEU 11/10/2018

Shear Stress Calculation Length (L): 3.9µm; Diameter (D): 16nm; Aspect Ratio (A): 243.75, Force Applied: 570.8nN I = Π/64 (D4) B = 5% of D = 0.05*D τ- = τ EI / BL3 = τ E П / 0.05*64*A3 Dimensionless Shear Stress (τ): 350 Calculated Frictional Shear Stress (τ-): 23.8 MPa Dana Research Centre, NEU 11/10/2018

Manipulation Example on SiO2 SIO2 Substrate Dana Research Centre, NEU 11/10/2018

Manipulation Procedure Original CNT After Manipulation Dana Research Centre, NEU 11/10/2018

CNT Length Measurement Dana Research Centre, NEU 11/10/2018

CNT Diameter Measurement Diameter: 12nm Dana Research Centre, NEU 11/10/2018

Experimental Curve Extraction Dana Research Centre, NEU 11/10/2018

Experimental and Theoretical Fit Increasing value of Shear Stress Dana Research Centre, NEU 11/10/2018

Shear Stress Calculation Case 1: Length (L): 1.2µm; Diameter (D): 12nm; Aspect Ratio (A): 100, Force Applied: 350.91nN I = Π/64 (D4) B = 5% of D = 0.05*D τ = Г EI / BL3 = Г E П / 0.05*64*A3 Dimensionless Shear Stress : 450 Calculated Frictional Shear Stress: 441.7MPa Dana Research Centre, NEU 11/10/2018

Manipulation Procedure Original CNT After Manipulation Dana Research Centre, NEU 11/10/2018

CNT Length Determination Length: 2.3µm Dana Research Centre, NEU 11/10/2018

CNT Diameter Determination Diameter: 10nm Dana Research Centre, NEU 11/10/2018

Experimental Curve Extraction Dana Research Centre, NEU 11/10/2018

Experimental and Theoretical Fit Increasing value of shear stress Dana Research Centre, NEU 11/10/2018

Shear Stress Calculation Case 2: Length (L): 2.3µm; Diameter (D): 10nm; Aspect Ratio(A): 230, Force Applied: 369.81nN I = Π/64 (D4) B = 5% of D = 0.05*D τ = Г EI / BL3 = Г E П / 0.05*64*A3 E = 1x1012 Dimensionless Shear Stress (Г) : 600 Calculated Frictional Shear Stress (τ ): 48.4 MPa Dana Research Centre, NEU 11/10/2018

Manipulation Example on Gold Gold Substrate Dana Research Centre, NEU 11/10/2018

CNT Manipulation Dana Research Centre, NEU 11/10/2018 Original CNT After Manipulation Dana Research Centre, NEU 11/10/2018

CNT Length Determination Length: 2.3µm Dana Research Centre, NEU 11/10/2018

CNT Diameter Determination Diameter: 28nm Dana Research Centre, NEU 11/10/2018

Experimental Curve Extraction Dana Research Centre, NEU 11/10/2018

Experimental and Theoretical Fit Increasing value of Shear Stress Dana Research Centre, NEU 11/10/2018

Shear Stress Calculation Case 7: Length (L): 2.3µm; Diameter (D): 28nm; Aspect Ratio (A): 82, Force Applied: 289nN I = Π/64 (D4) B = 5% of D = 0.05*D τ = Г EI / BL3 = Г EI П / 0.05*64*A3 E = 1x1012 Dimensionless Shear Stress : 150 Calculated Frictional Shear Stress: 267 MPa Dana Research Centre, NEU 11/10/2018

CNT Manipulation Dana Research Centre, NEU 11/10/2018 Original CNT After Manipulation Dana Research Centre, NEU 11/10/2018

CNT Length Determination Length: 3.2µm Dana Research Centre, NEU 11/10/2018

CNT Diameter Determination Diameter: 12nm Dana Research Centre, NEU 11/10/2018

Experimental Curve Extraction Dana Research Centre, NEU 11/10/2018

Experimental and Theoretical Fit Increasing values of Shear Stress Dana Research Centre, NEU 11/10/2018

Shear Stress Calculation Case 8: Length (L): 3.2µm; Diameter (D): 12nm; Aspect Ratio (A): 266.7 Force Applied: 489nN I = Π/64 (D4) B = 5% of D = 0.05*D τ = Г EI / BL3 = Г E П / 0.05*64*A3 E = 1x1012 Dimensionless Shear Stress : 100 Calculated Frictional Shear Stress:5.1 MPa Dana Research Centre, NEU 11/10/2018

Manipulation Example on Thiol Thiol (Octadenathiol) on Gold Substrate Dana Research Centre, NEU 11/10/2018

CNT Manipulation Dana Research Centre, NEU 11/10/2018 Original CNT After Manipulation Dana Research Centre, NEU 11/10/2018

CNT Length Determination Length: 3.9µm Dana Research Centre, NEU 11/10/2018

CNT Diameter Determination Diameter: 5nm Dana Research Centre, NEU 11/10/2018

Experimental Curve Extraction Dana Research Centre, NEU 11/10/2018

Experimental and Theoretical Fit Range of shear stress value Median value of 75 considered for shear stress calculation Increasing value of shear stress Dana Research Centre, NEU 11/10/2018

Shear Stress Calculation Case 9: Length (L): 3.90µm; Diameter (D): 6nm; Aspect Ratio (A): 650, Force Applied: 719nN I = Π/64 (D4) B = 5% of D = 0.05*D τ = Г EI / BL3 = Г E П / 0.05*64*A3 E = 1x1012 Dimensionless Shear Stress (Г) : 75 Calculated Frictional Shear Stress (τ ): 0.2 MPa Dana Research Centre, NEU 11/10/2018

CNT Manipulation Dana Research Centre, NEU 11/10/2018 Original CNT After Manipulation Dana Research Centre, NEU 11/10/2018

CNT Length Determination Length: 1.80µm Dana Research Centre, NEU 11/10/2018

CNT Diameter Determination Diameter: 23nm Dana Research Centre, NEU 11/10/2018

Experimental Curve Extraction Dana Research Centre, NEU 11/10/2018

Experimental and Theoretical Fit Range of shear stress value Median value of 85 considered for shear stress calculation Increasing value of shear stress Dana Research Centre, NEU 11/10/2018

Shear Stress Calculation Case 10: Length (L): 1.80µm; Diameter (D): 23nm; Aspect Ratio (A): 80.8, Force Applied: 380nN I = Π/64 (D4) B = 5% of D = 0.05*D τ = Г EI / BL3 = Г E П / 0.05*64*A3 E = 1x1012 Dimensionless Shear Stress (Г ): 85 Calculated Frictional Shear Stress (τ ): 158MPa Dana Research Centre, NEU 11/10/2018

Results Summary Dana Research Centre, NEU 11/10/2018 Earlier Manipulation Procedure Our Manipulation Procedure Sl No Dia [nm] Length [µm] Aspect ratio Point of Load app Shear stress (Theory) Shear stress [Mpa] Silicon Dioxide (SiO2) 1 12 1.2 100 0.48 450 441.7 2 10 2.3 230 0.5 600 48.4 3 16 3.9 243.7 350 23.8 4 1.6 0.45 500 490.8 Gold 7.5 4.9 653 0.49 45 0.2 8.5 2.5 294 550 21.2 28 82 150 267 3.2 266.7 5.1 Thiol 6 650 75 23 1.8 80.8 85 158 Dana Research Centre, NEU 11/10/2018

Discussion Dana Research Centre, NEU 11/10/2018 Wider range of Aspect Ratio Tubes yields wide range of shear stress values Consistent point of load application, providing good opportunity for best deformation behavior CNT manipulation on Thiol is easy Non uniform CNT deformation on Thiol Partial tube movement, Cutting of tubes, Similar to CNT rolling behavior observed Need more precise tracking of the CNT Movement along the surface, according to the vector drawn Precise CNT movement tracking possible only with clean surface Vacuum manipulation and measurements a good idea AFM Tip nature does influence manipulation results Dana Research Centre, NEU 11/10/2018

Conclusion Dana Research Centre, NEU 11/10/2018 Simple Effective manipulation procedure established Progress in obtaining better values of shear stress has been made Theoretical Curve generation for any point of load application provides flexibility in manipulation Aspect ratio for CNT manipulation has been increased from 80-650 Manipulation procedure needs some improvements Dana Research Centre, NEU 11/10/2018

Master Thesis Dana Research Centre, NEU Questions ??? Comments !!! Complaints.., Thank You Dana Research Centre, NEU 11/10/2018