Additive nanomanufacturing: a review

Additive manufacturing has provided a pathway for inexpensive and flexible manufacturing of specialized components and one-off parts. At the nanoscale, such techniques are less ubiquitous. Manufacturing at the nanoscale is dominated by lithography tools that are too expensive for small- and medium-sized enterprises (SMEs) to invest in. Additive nanomanufacturing (ANM) empowers smaller facilities to design, create, and manufacture on their own while providing a wider material selection and flexible design. This is especially important as nanomanufacturing thus far is largely constrained to 2-dimensional patterning techniques and being able to manufacture in 3-dimensions could open up new concepts. In this review, we outline the state-of-the-art within ANM technologies such as electrohydrodynamic jet printing, dip-pen lithography, direct laser writing, and several single particle placement methods such as optical tweezers and electrokinetic nanomanipulation. The ANM technologies are compared in terms of deposition speed, resolution, and material selection and finally the future prospects of ANM are discussed. This review is up-to-date until April 2014

Electron beam induced deposition (EBID) of carbon interface between carbon nanotube interconnect and metal electrode

Electron Beam Induced Deposition (EBID) is an emerging additive nanomanufacturing tool which enables growth of complex 3-D parts from a variety of materials with nanoscale resolution. Fundamentals of EBID and its application to making a robust, low-contact-resistance electromechanical junction between a Multiwall Carbon Nanotube (MWNT) and a metal electrode are investigated in this thesis research. MWNTs are promising candidates for next generation electrical and electronic devices, and one of the main challenges in MWNT utilization is a high intrinsic contact resistance of the MWNT-metal electrode junction interface. EBID of an amorphous carbon interface has previously been demonstrated to simultaneously lower the electrical contact resistance and to improve mechanical characteristics of the MWNT-electrode junction. In this work, factors contributing to the EBID formation of the carbon joint between a MWNT and an electrode are systematically explored via complimentary experimental and theoretical investigations. A comprehensive dynamic model of EBID using residual hydrocarbons as a precursor molecule is developed by coupling the precursor mass transport, electron transport and scattering, and surface deposition reaction. The model is validated by comparison with experiments and is used to identify different EBID growth regimes and the growth rates and shapes of EBID deposits for each regime. In addition, the impact of MWNT properties, the electron beam impingement location and energy on the EBID-made carbon joint between the MWNT and the metal electrode is critically evaluated. Lastly, the dominant factors contributing to the overall electrical resistance of the MWNT-based electrical interconnect and relative importance of the mechanical contact area of the EBID-made carbon joint to MWNT vs. that to the metal electrode are determined using carefully designed experiments.Ph.D.Committee Chair: Dr. Andrei G. Fedorov; Committee Member: Dr. Azad Naeemi; Committee Member: Dr. Suresh Sitaraman; Committee Member: Dr. Vladimir V. Tsukruk; Committee Member: Dr. Yogendra Josh

Analisa Hasil Simulasi Sifat Mekanik Single-Walled Carbon Nanotube dengan Variasi Struktur dibawah Pembebanan Bending dan Buckling Menggunakan FEM

Carbon nanotube merupakan material allotropi carbon yang memiliki sifat mekanik, thermal dan elektrik cukup baik. Saat ini para peneliti masih banyak menganalisa kebutuhan sifat mekanik yang tepat untuk dapat diterapkan lebih diberbagai bidang. Ukurannya yang nano membuat sulitnya pengujian untuk menganalisa sifat dan perilaku CNT. Sehingga diperlukan adanya simulasi komputasi untuk menyederhanakan penelitian. Hasil simulasi dibuat untuk menganalisa sifat mekanik berupa modulus elastisitas SWCNT dengan membandingkan variasi struktur tipe zigzag dan armchair menggunakan software ANSYS 17.1 Mechanical APDL. Hasil simulasi juga digunakan untuk menganalisa pengaruh diameter, ketebalan, dan aspek rasio terhadap nilai Young’s modulus SWCNT. Diperoleh bahwa struktur yang sesuai untuk aplikasi yang membutuhkan tingkat kelenturan yang tinggi akibat pembebanan bending dan buckling adalah struktur armchair. Dimana semakin besar diameter single walled carbon nanotube maka nilai Young’s modulusnya. Semakin meningkat. Dan semakin tinggi aspek rasio dan ketebalan struktur SWCNT maka semakin rendah nilai Young’s modulusnya. ======================================================================================================= Carbon nanotube is a carbon allotropy which has good mechanical, thermal and electrical properties. Currently the researchers are still analyzing the right properties for their right properties in composites. Those Nano size make CNT rather hard to analyze the behavior of CNTs in form of experiment. A simulation is needed to simplify the research. Therefore, this study was made to analyze the simulation results of SWCNT’s modulus elasticity by comparing structural variations of the zigzag and armchair types using finite element method software ANSYS 17.1 Mechanical APDL. Simulation result used for analyzing diameter and aspect ratio effect on the structure of SWCNT. The suitable structure which need high elasticity caused by bending and buckling loading is armchair type of SWCNT. The highest diameter of SWCNT, the higher Young’s modulus value is. And the higher aspect ratio and the thickness structure of SWCNT, the lower Young’s modulus had

Low-dimensional carbon nanotube and graphene devices

P.iii (acknowledgements) missing from electronic version.Electronic devices in which the electrons are confined to fewer than three spatial dimensions are an important tool for physics research and future developments in computing technology. Recently discovered carbon nanotubes (1991) and graphene (2004) are intrinsically low-dimensional materials with remarkable electronic properties. Combined with semiconductor technologies they might be used to fabricate smaller devices with more complex functionality. This thesis addresses two routes towards this goal. The detection of charge transport through quantum dots using a GaAs point contact is a potential tool for quantum computation. This project aimed to fabricate and measure hybrid devices with carbon nanotube quantum dots on top of GaAs point contacts. Dispersion and AFM manipulations of nanotubes on GaAs were studied, revealing comparatively weak binding. Transport measurements indicated that GaAs induces disorder in nanotubes, creating multiple tunnel barriers. Preliminary attempts were made at CVD growth and ink-jet printing of nanotubes directly onto GaAs. Although only one atom thick, graphene is macroscopic in area and must be patterned to confine conduction; room temperature transistor behaviour requires graphene ribbons only a few nanometres wide. This work fabricated such structures using a charged AFM tip, achieving reliable cutting even on single layer graphene and feature sizes as small as 5 nm. The cutting mechanism was found to be chemical oxidation of carbon by a polarised water layer, with an activation energy determined by the energy of dissociation of water at the graphene surface. The critical variables were the voltage difference between the tip and graphene and the atmospheric humidity. An unstable solid oxide intermediate was also observed. Thermal annealing revealed the presence of a layer of water beneath flakes. Finally, EFM measurements were made of graphene at 20 mK, enabling estimates of the local carrier density and revealing spatial variations in the electronic structure on a scale consistent with electron and hole puddles

Multi-axis compliant mechanism-based nanopositioner for multi-mode mechanical testing of carbon nanotubes

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (p. 116-118).This thesis documents the design of a multi-axis nanopositioner that addresses a need for carbon nanotube (CNT) instrumentation that is capable of multiple modes of mechanical testing. This nanopositioner is a solution to the need to quantify the mechanical properties of CNTs with the appropriate modes of testing, such as simultaneous bending and tensile loading. This information is important as it is required to test and better understand the properties of CNTs before and after they are used in micro/nano-structures. The multi-axis nanopositioner will be integrated as one of the core components in a new CNT instrument that is presented in this thesis. The nanopositioner is a compliant mechanism-based device designed that is to induce precise nanometer-level deformations in CNTs within a scanning electron microscope (SEM). The design presented in this thesis is a 4-axis prototype of a 6-axis version. The 4-axis nanopositioner was able to demonstrate over one micron range of motion in multiple axes with 10 nm resolution and repeatability. The nanopositioner was specifically designed to fit inside an SEM like an ordinary sample.by Kevin Lin.S.M

Physical properties of carbon nanotube/graphene junctions

New connecting techniques for graphene have to be developed to ensure a better device integration for this astonishing material. The use of carbon nanotubes, a material closely related to graphene as connecting material is a promising option to explore. In this work, the interface between carbon nanotube and graphene has been addressed. A range of properties have been determined ranging from structural parameters to electrical transport behaviour

Advanced Knowledge Application in Practice

The integration and interdependency of the world economy leads towards the creation of a global market that offers more opportunities, but is also more complex and competitive than ever before. Therefore widespread research activity is necessary if one is to remain successful on the market. This book is the result of research and development activities from a number of researchers worldwide, covering concrete fields of research

MICROCANTILEVER-BASED FORCE SENSING, CONTROL AND IMAGING

This dissertation presents a distributed-parameters base modeling framework for microcantilever (MC)-based force sensing and control with applications to nanomanipulation and imaging. Due to the widespread applications of MCs in nanoscale force sensing or atomic force microscopy with nano-Newton to pico-Newton force measurement requirements, precise modeling of the involved MCs is essential. Along this line, a distributed-parameters modeling framework is proposed which is followed by a modified robust controller with perturbation estimation to target the problem of delay in nanoscale imaging and manipulation. It is shown that the proposed nonlinear model-based controller can stabilize such nanomanipulation process in a very short time compared to available conventional methods. Such modeling and control development could pave the pathway towards MC-based manipulation and positioning. The first application of the MC-based (a piezoresistive MC) force sensors in this dissertation includes MC-based mass sensing with applications to biological species detection. MC-based sensing has recently attracted extensive interest in many chemical and biological applications due to its sensitivity, extreme applicability and low cost. By measuring the stiffness of MCs experimentally, the effect of adsorption of target molecules can be quantified. To measure MC\u27s stiffness, an in-house nanoscale force sensing setup is designed and fabricated which utilizes a piezoresistive MC to measure the force acting on the MC\u27s tip with nano-Newton resolution. In the second application, the proposed MC-based force sensor is utilized to achieve a fast-scan laser-free Atomic Force Microscopy (AFM). Tracking control of piezoelectric actuators in various applications including scanning probe microscopes is limited by sudden step discontinuities within time-varying continuous trajectories. For this, a switching control strategy is proposed for effective tracking of such discontinuous trajectories. A new spiral path planning is also proposed here which improves scanning rate of the AFM. Implementation of the proposed modeling and controller in a laser-free AFM setup yields high quality image of surfaces with stepped topographies at frequencies up to 30 Hz. As the last application of the MC-based force sensors, a nanomanipulator named here MM3A® is utilized for nanomanipulation purposes. The area of control and manipulation at the nanoscale has recently received widespread attention in different technologies such as fabricating electronic chipsets, testing and assembly of MEMS and NEMS, micro-injection and manipulation of chromosomes and genes. To overcome the lack of position sensor on this particular manipulator, a fused vision force feedback robust controller is proposed. The effects of utilization of the image and force feedbacks are individually discussed and analyzed for use in the developed fused vision force feedback control framework in order to achieve ultra precise positioning and optimal performance