Connect with IEN

Georgia Institute of Technology
The Institute for Electronics and Nanotechnology

2018 Summer Undergraduate Research Program In Nanotechnology

 
SENIC—Southeastern Nanotechnology Infrastructure Corridor part of the National Nanotechnology Coordinated Infrastructure.

 

Start the Application Process

Application deadline February 16, 2018

 
PHYSICS, CHEMISTRY, ENGINEERING & BIOSCIENCES
Explore exciting interdisciplinary opportunities in nanoscale science and engineering at Georgia Tech's IEN facilities
PROGRAM DATES
May 29-August 7
WIDE RANGE OF RESEARCH
Nanofabrication
Microfluidics
Nanostructures
Chemical & Biological sensors
Polymers
Optics
10 WEEK PROGRAM
  • $5,000 Stipend
  • Travel
  • Housing
 

Summer Project Opportunities

1) Microsensors with Nanostructured Surfaces Fabricated by 3D Lithography - Prof. Oliver Brand, School of Electrical and Computer Engineering, Executive Director, Institute for Electronics and Nanotechnology, Director of SENIC and NNCI
Through a recent NSF MRI award (ECCS- 1626078), a commercial 3D lithography system with sub-micrometer resolution based on 2-photon polymerization was installed in Georgia Tech’s shared-use cleanroom facilities in Spring 2017. The system allows for writing of arbitrary-shaped 3D patterns with a resolution down to 150nm into light-sensitive polymers with applications ranging from photonics and MEMS to cell biology and tissue engineering. The main goal of the REU project is to modify surfaces of (silicon-based) microsensors with 3D-printed nanoscale features. Of particular interest are surfaces of mass-sensitive chemical sensors that are currently investigated in our laboratory for gas- and liquid-phase sensing applications. These cantilever-type resonators have a head region, which is normally spray-coated with a µm-thick polymeric sensing film. While a thick sensing film improves sensor sensitivity, it also slows down the sensor response as analyte needs to diffuse into the relatively thick sensing film. High-surface area, nano-structured sensing films are a way to improve response times while still providing sufficient sensor sensitivity. To this end, the student will develop processes on the 3D direct-write lithography system to write high-surface-area nanopatterns, such as nanopillar arrays, directly on the sensing surfaces of silicon-based hammerhead resonators available in our lab. Thereby, the challenge lies in writing 3D nanopatterns directly onto already fabricated microsensors, rather than on a new substrate, such as a wafer or glass slide. The resulting chemical sensors with nanostructures surfaces can be tested using gas-mixing systems available in our lab. In addition to the impact of the nanostructured surfaces on the chemical sensing performance, we will explore whether nanopatterns on the surface of the resonator can impact the damping losses by reducing surface friction, similar to how nanostructures can provide super-hydrophobic surfaces. The project will introduce the REU student to chemical microsensor technologies as well as state-of-the-art additive nano-manufacturing techniques.

2) Inkjet printing of Graphene and Carbon Nanotube Suspensions - Prof. Rosario Gerhardt, Goizueta Foundation Faculty Chair, School of Materials Science and Engineering
The main goal of this project is to determine the best conditions for inkjet deposition of patterned graphene and/or carbon nanotube particulate thin films. These materials have excellent electrical and optical properties that make them suitable for use as electrodes in a variety of devices as well as the main active components of supercapacitors, sensors and display devices. The advantages of inkjet printing are that material waste is minimized and the number of layers deposited determine the resultant properties. Most solution deposition methods such as spin coating, dip-coating and spray pyrolysis can enable low-cost mass production without requiring strict vacuum conditions and material waste. However, in order to achieve patterned films, these solution-processed methods still need photolithography and etching steps which result in significant material waste. One way to prevent these costly steps and simplify the processing is by using ink-jet printing. Graphene and carbon nanotube inks can be either commercially obtained and/or fabricated in house. The research group has substantial experience with working with nanoparticulate thin films and has succeeded in making patterned ITO nanoparticulate films. The research questions the REU student will address include: 1. What is the best concentration and size of graphene nanoflakes and/or carbon nanotubes to deposit patternable thin films? 2. Once that is determined, the student intern will be directed to determine what is the best resolution that can be achieved and to establish how many inkjet printed layers are needed to achieve different levels of electrical conductivity and transparency?  The REU student will be expected to do this for at least three different values of electrical conductivity.

3) Development of ultra-low power gas sensor arrays for monitoring of ambient air quality - Prof. Peter Hesketh,  Woodruff School of Mechanical Engineering
The project will explore micro-thermal conductivity gas sensors for CO2 and methane sensing. The sensors are based on detecting the modulation of the thermal conductivity of the surrounding medium. The limit of detection in nitrogen was determined to be 25 ppm for helium and 178 ppm for carbon dioxide. The sensors require less than 8 nJ for a measurement and need only 300 µs to acquire data. This allows measurements at much higher sample rates with extremely low power consumption. The proposed projects will provide research and education opportunities for undergraduate students to gain experience with the characterization of gas sensors and their use for measurement of ambient air quality. Students will be exposed to microfabrication methods and MEMS technology for the manufacture of low-cost and ultra-low power gas sensors. Student will analyze data from sensor arrays and use statistics to evaluate the limit of detection, dynamic range and reproducibility of sensors operating under various condition, such as temperature and humidity levels.

4) New Dielectrics for Microelectronic Devices - Prof. Paul Kohl, Regents Professor, Institute Fellow, Hercules Inc./Gossage Chair, Georgia Tech, School of Chemical and Biomolecular Engineering
Sacrificial materials have been used to create embedded air-cavities in integrated circuits, MEMS packaging, and microfluidics. Additionally, sacrificial polymers can be used for vaporizable substrates for transient electronic devices. Tuning the thermal decomposition behavior of the sacrificial polymer can provide unique advantages for various applications. Two routes to the thermal decomposition of poly(propylenecarbonate) (PPC) have been considered: polymer chain-end unzipping and random chain scission. The inhibition and catalysis of each mechanism will be studied. End-capping the chain ends has been achieved and additives have been used to stabilize the backbone. Catalysts such as photo-acid/base generators were incorporated into films and used to catalyze decomposition pathways of PPC. Approaches into reducing the amount of non-volatile catalyst with more volatile acid-amplifying compounds will be explored. An optical trigger for the catalyst will explored with the goal of catalyzing the depolymerization with sunlight. Residue of the sacrificial polymers with catalyst additives will be quantified after decomposition. The student will learn specific steps in the organic synthesis of sacrificial polymers and their characterization. The activities include purification of starting materials via distillation or sublimation, the end-capping of polymers via a condensation reaction, and characterization of the products via nuclear magnetic resonance spectroscopy and gel permeation chromatography.

5) Materials Design for Efficient Photocatalysis and Corrosion Inhibition - Prof. Kimberly E. Kurtis, School of Civil and Environmental Engineering, Assoc. Dean, College of Engineering
This research builds upon the hypothesis that amorphous and crystalline phases present in hydrated cement-based materials can be exploited to serve as a smartsink for NO2-/NO3- (NOx) species which are bound within the concrete during photocatalytic oxidation. In one reaction pathway, under conditions of Cl- intrusion, the NO2-/NO3- AFm phases initially present react with intruding Cl- species (effectively binding these aggressive ions) and via an anion exchange mechanism simultaneously release NO2-/NO3- species into the pore solution, where they act as anodic corrosion inhibitors. This inhibition mechanism is maintained a long as the appropriate AFm phase buffers NO2-/NO3- levels to the limit of its anion exchange capacity, after which progressive increases in Cl- ion intrusion are matched by increasing abundances of aqueous NO2-/NO3- species sourced by photocatalytic oxidation (PCO) of atmospheric NOx. This hypothesis is explored under NSF CMMI-1362843. This regenerative and tunable method of corrosion inhibition offers new opportunities for advanced materials design, which is the focus of the research proposed under this award. Successful development of enhanced materials can, for example, significantly extend the life of bridge decks, which are particularly susceptible to corrosion, vital in their intended purpose, and involve high environmental and economic costs for replacement. Material composition and structure (e.g., functional gradients in specific surface area, pore structure) can be designed to enhance the rates of NOx and Cl- binding and NO2-/NO3transport. Fundamental understanding of the complex mechanisms of surface PCO and transport are necessary to identify appropriate cement compositions (e.g., consider use alternate binder chemistries to increase AFm content) and pore structures. Using a photocatalytic reactor, the REU student will explore binding mechanisms and rates under varying conditions. The student will accomplish this with ex situ advanced characterization using ToF SIMS (time-of-flight secondary ion mass spectroscopy) and RAMAN spectroscopy, as well as x-ray diffraction, to understand the rates of ionic species binding, the products formed, and the rates of ionic transport. Resulting process models will be used to enhance the functionality, efficiency, and sustainability of cement-based materials designed for this purpose.

6) Planarized Transistors for Advanced Characterization of Inter- and Intrachain Charge Transport in Organic Electronics - Prof. Elsa Reichmanis, Brooks Byers Professor, School of Chemical and Biomolecular Engineering
Organic electronics offer an emerging new paradigm for electronic devices. Over the past few decades both small molecules and polymer systems have displayed great potential for use in organic field effect transistors (OFETs), organic photovoltaics (OPVs), radio frequency ID tags (RFID) and biocompatible sensors for medical applications. Conjugated polymers have received attention because of their ability to be solution processed at ambient conditions. Compared to their traditional inorganic counter parts and small molecules that require high temperatures and pressures, conjugated polymers are expected to enable large area and cost effective electronic devices. The electrical performance of conjugated polymer devices is highly dependent on the microstructure and morphology of the final film structure. Poly(3-hexylthiophene) (P3HT) has been used as a model conjugated polymer due to its commercial availability to explore elusive process-structure-property relationships. Recent processing methods have been developed that result in densely packed and highly aligned fibers. However, understanding the mechanisms of anisotropic charge transport through this semi-crystalline fiber network has been limited. The bottom gate, bottom contact transistor architecture commonly utilized in charge mobility studies introduces unequal flow patterns when blade coating a polymer solution parallel and perpendicular to the source/drain. Thus, previous attempts to investigate the roles of inter- and intrachain charge transport have been unable to decouple flow effects and charge transport anisotropy.  In this study, we propose the development of planarized transistors to investigate the mechanisms of anisotropic charge transport using P3HT. The intern will fabricate planarized transistors by selectively etching into the silicon dioxide layer and depositing gold electrodes flush with the surface. He/she will dissolve P3HT in chloroform, nucleate with UV-irradiation to induce aggregation and then blade-coat parallel and perpendicular to the source and drain electrodes. Combinational analysis of high (95 kDa) and low (37 kDa) P3HT will be used to modulate fiber length and packing density and to investigate the role of so-called ‘tie chains’ to connect crystalline fiber domains. This project will leverage expertise in electronic device fabrication to address fundamental questions on inter- and intra-chain charge transport in organic polymeric devices.

7) Compact Light Sources for Biological Applications - Prof. Shyh-Chian Shen, School of Electrical and Computer Engineering
The advancement of light-emitting-diode (LED) technologies have enabled immense opportunities to implement energy-efficient compact light sources for future applications, not only in the commonly known consumer electronics products but also in specialized research fields. For example, ultraviolet (UV) LEDs can replace bulky mercury lamps and help the realization of highly sensitive bacteria detection systems to monitor real-time environmental conditions. In this project, the undergraduate researcher will explore another aspect of LED applications - for plant growth enhancement. It is known that most plants respond to specific wavelengths of the solar spectrum (typically in the wavelengths of 500-900 nm), and LEDs emitting photons in these wavelengths are commercially available and are the perfect light source for plants. The student will build arrays of LEDs and will control the light emission spectrum and intensity using an Arduino circuit board.  A CCD camera will be built onto the circuit board to perform automatic snapshots of the plant under study to observe differences in the growth rate and the response of the plants to different photon energies.  The outcomes of the research project are expected to provide the undergraduate researcher: (1) an understanding of how LEDs work and how to manipulate these devices to emit a desired engineered optical spectrum; (2) an exploration and understanding of system automation and control using circuit boards and computer programming; and (3) a link of electrical engineering and biology fields for broader technological impacts.

8) Microfluidic Devices for Delivering Particles to Cells - Prof. Todd Sulchek, Woodruff School of Mechanical Engineering
The overall goal of the project is to build and test microfluidic devices to deliver particles to cells via repeated cell compressions. The significance of this research is to improve the ability to deliver nanoparticle sensors to cells to report the expression of macromolecules within the cells indicative of cancer and other diseases. Personalized treatment strategies are generally guided by an analysis of molecular biomarkers of the tumor, which contain information to elucidate mechanisms for how a metastatic tumor will evolve and spread. Liquid biopsies conventionally use cell surface markers as a readout of cell state, yet these markers may only loosely indicate the specific state of a particular cancer cell. Intracellular markers are more faithful indicators of cell state, but these lack a routine approach for examining at high throughput, particularly if the cells are to be kept viable for more full downstream analyses. New methods to evaluate cellular heterogeneity will be the key to personalized prognosis and treatment. The project’s aim is to validate a process of high-throughput, single cell, live cell labeling to be able to profile cancer cells. The student will design, build, and test microfluidic devices to process cells to enable delivery of nanoparticle sensors into the cell interior. The student will also test design features to enhance the cell processing rate to lead to higher throughput. The student will design devices in a CAD software, build molds in the IEN cleanroom, and make devices from these molds using replica molding. A variety of device designs will be tested to evaluate cell delivery efficiency and processing rate.

9) Circuit Simulation of Low-Power Compact Oscillators Based on Two-dimensional Heterostructures - Prof. Eric Vogel, School of Materials Science and Engineering, Deputy Director IEN and Associate Director of Institute for Materials
Circuit architectures based on coupled oscillators have the potential for pattern recognition, associative memory and logic applications with orders of magnitude better power and performance as compared to conventional digital CMOS. Historically, devices that exhibit negative differential resistance (NDR), such as resonant tunneling diodes (RTDs), have been used for oscillators. However, widespread application of these devices has been limited due to relatively small peak-to-valley ratio, a large area footprint and significant device-to-device variation. RTDs based on heterostructures of two-dimensional materials (such as graphene and MoS2) exhibit a theoretical peak-to-valley ratio substantially greater than those based on conventional semiconductors. Furthermore, graphene exhibits large values of kinetic inductance even at the nanoscale. Therefore, the overall research focuses on synthesized 2D heterostructures and their intrinsic inductance and capacitance for compact RTD oscillators with properties that can overcome limitations of 3D semiconductor RTDs and achieve highly integrated, low-power, high-speed, oscillator-based computational circuits. A key aspect of the overall research is to develop an understanding of the impact of RTD device properties on the performance of oscillators using SPICE simulation. The undergraduate researcher will use simple parametric models to change parameters that strongly influence oscillator circuits such as the peak/valley voltage/current and the negative resistance. Initial simulations of the oscillator circuits as a function of these key parameters will be used to determine the range of I-V characteristics and parameters (inductance/capacitance) necessary to achieve stability, low-power and high performance.

10) Synthesis of Palladium Icosahedral Nanocrystals with High Morphology Yield - Prof. Younan Xia, Brock Family Chair, GRA Eminent Scholar in Nanomedicine, School of Chemical and Biomolecular Engineering
Palladium icosahedra are twenty-sided nanoparticles (NPs) that are enclosed by {111} facets. They contain twinned defects and larger numbers of vertices and edges, enabling them to surpass Pd single-crystal NPs in terms of effectiveness for applications, such as hydrogen absorption and formic acid oxidation. Pd icosahedra can also be used as templates to obtain Pt-based icosahedral nanocages, a new class of catalysts for the oxygen reduction reaction (ORR), which have 6.7-fold and 10-fold enhancements relative to commercial Pt/C in regards to mass and specific activities. The existing synthesis method is based on a polyol process. This method can be used to readily synthesize Pd icosahedra with sizes from 10-12 nm. However, it suffers from a low morphology yield of around 10−15% for 10-nm Pd icosahedra, which makes the process not suitable for large-scale applications. The research will take multiple strategies to improve the morphology yield of Pd icosahedra (>80%). The main cause of the low morphology yield is that there are many small NPs which do not grow to the right size and are lost during post-synthesis centrifugations. The intern’s research will focus on enhancing the reducing power of the reductant, through the introduction of either an external reducing agent or a basic environment, to fully grow these underdeveloped small NPs without causing more self-nucleation. Initial results show that the introduction of 100mg ascorbic acid into the reaction solution can increase the morphology yield to 35.5%. Fine-tuning the adding time of ascorbic acid, total reaction time, amount of ascorbic acid, and types of external reducing agents will be studied to further increase the morphology yield. Alternatively, providing a basic environment is also capable of increasing the reducing kinetics. We will try to use bases such as sodium hydroxide (NaOH) to increase the reducing power of the polyol. Other factors such as reaction temperature and different polyols will also be investigated to effectively increase the morphology yield. 

 

For more details please read our

Frequently Asked Questions