If you would like to give a smallTalk lecture, please contact nanotech@ualberta.ca.
Lectures take place in NINT Taylor room, which is accessible to public via the east entrance of the NINT building.

Upcoming smallTalk:

Date and Time: June 9, 2016 at 12:00pm
Speaker: Dr. Alex Brown, Department of Chemistry
Title: "Computational Chemistry: From small molecule quantum dynamics to bioimaging to new materials"

Abstract: The interpretation of modern experimental measurements and syntheses in chemistry is greatly aided through a variety of sophisticated computational chemistry techniques (in particular ab initio electronic structure methods). These methods can be used for determining molecular geometries, bonding (electronic structure), and physical as well as photophysical properties of molecules. Computational chemistry can go beyond simply interpreting existing experiments to the prediction of new species with novel properties. In this talk, I will highlight recent examples from our work including: understanding and laser control of the dynamics of small (3-4 atoms) polyatomic molecules; designing fluorescent proteins with strong two-photon absorptions for biological imaging; and understanding phosphorescent tellurophene-compounds for materials chemistry. From these examples, I will showcase the strong role computational chemistry plays in modern chemistry research. 

Past smallTalks:

Date and Time: November 27, 2015 at 12:00pm
Speaker: Dr. Juli Gibbs-Davis, Department of Chemistry
Title: "Tuning Molecular Recognition in DNA-Based Materials"

Abstract: Our group is interested in understanding how confinement influences molecular recognition in materials systems and how we can use its unique influence to achieve new material properties. In one example, we have developed a DNA system that can self-replicate isothermally by balancing repulsive and attractive interactions during DNA recognition. This strategy of amplification by destabilization has great potential in DNA diagnostics and infectious disease detection as it utilizes very simple DNA modifications and can be performed at virtually any temperature. In another example, we have shown that using molecular recognition we can control the composition and behavior in DNA nanomaterials that are potential candidates for targeted drug delivery. By exploring the unique molecular recognition properties of these same materials, we have also uncovered a strategy for rapid colorimetric detection of DNA suitable for point-of-care diagnostics. Finally, I will discuss how confinement at planar silica surfaces most relevant to microarray technologies influences DNA recognition using surface specific spectroscopy. We find that confinement at the silica interface greatly reduces the stability of DNA duplexes in comparison with other common substrates like gold, which has direct implications for biodiagnostics using DNA immobilized on glass. 

Date and Time: October 2, 2015 at 12:00pm
Speaker: Dr. Carlo Montemagno, Department of Chemical and Materials Engineering - National Institute of Nanotechnology
Title: "Thinking Small to Define a Big Future"

Abstract: The ability to use machines to manipulate matter a single molecule at a time renders many things possible that were impossible before. Living systems do this on a regular basis. The core challenge is how to transform a labile molecule that exists in a fragile living organism and to transfer that functionality into a stable system that is economically scalable. The most significant difficulties revolve around environmental stability and the inherent structural limitations of the molecule.
Presented is the generic solution methodology used to solve these limiting challenges to produce a new class of materials and devices. Elements of the discussion will include the genetic engineering of active biological molecules into engineering building blocks and their assembly to introduce “metabolism” into engineered devices and materials. Ultimately synthesizing new classes of materials with advanced functionality that incorporates new intrinsic properties into the matter.
Two exemplars will be presented. First we will elucidate the design, engineering and assembly of a complex closed system that uses a highly modified photosynthetic process to transform carbon waste into valuable drop-in specialty chemicals without any living organisms with commercially competitive economics. Secondly we will present a new technology that stabilizes biological molecules maintaining their function for months at application relevant environmental conditions transitioning additive manufacturing from 3D space to a four-dimensional, functional space. Enabling the synthesis of a new class of printable “inks” that have stabilized and active biological molecules as integrated elements of synthesized polymer constructs to create a new class of materials that now includes biologic function as an intrinsic property.
The next wave of technological progress will enable the manufacturing of a unique class of devices and materials that embeds complex functional behavior as an intrinsic property enabling emergent functionality at multiple length scales. These systems will actively interact with their local environment establishing a new capability that will impact solution generation across multiple societal sectors including health care, resource recovery, food production and, environmental restoration.

Douglas Barlage

Date and Time: March 27, 2015 at 12:00pm
Speaker: Dr. Douglas Barlage, Department of Electrical and Computer Engineering
Title: "Advanced Materials Growth Techniques for High Performance Electronic Devices"

Abstract: Small transistors can yield big things and those transistors can be created by even smaller atomic interactions. At the very nano-scale, it involves designing and testing devices and materials to produce a compelling alternative to the best low power device architecture available -- silicon CMOS. At the very large, enhanced use of electronics stands to make great impacts in the power management systems of the future. Under both circumstances, while the size may be much different, the electric fields that are managed are nearly the same. Furthermore, power efficiency is critical to both applications and similar governing physical mechanisms require investigation. The simultaneous investigation of new materials and device architectures requires a rigorous, collaborative and very interdisciplinary approach. In this talk, I will describe how using advanced materials growth techniques leads to the highest performing electronic devices. Starting with silicon devices and the modern transistor with dimensions smaller than a strand of DNA. We will then see how the knowledge gathered here, applies to wide bandgap semiconductors of Galium Nitride and in the near future, material systems like Zinc Oxide.

Mark Freeman

Date and Time: February 13, 2015 at 12:00pm
Speaker: Dr. Mark Freeman, Department of Physics
Title: "Magnetic Resonance Torque Spectroscopy"

Abstract: Radio-frequency spectroscopy developed rapidly after the second world war. The detection of magnetic resonance by Faraday induction launched powerful, general-purpose probes of local electron and nuclear environments in matter, and led to MRI. Induction signals are progressively weaker for smaller specimens and lower resonance frequencies. This smallTalk will describe a magnetic resonance spectrometer, in which the precession of magnetic dipoles generates torque on a nanomechanical sensor. "Torque spectroscopy" is a general-purpose complement to existing methods.

Gabriel Hanna

Date and Time: November 27, 2014 at 12:00pm
Speaker: Dr. Gabriel Hanna, Department of Chemistry
Title: "Nanosolvation and Nanoconfinement Effects on Reactions in Hydrogen-Bonded Systems"

Abstract: Hydrogen bonding plays a crucial role in many chemical and biochemical reactions. These reactions often take place in nano-sized clusters of molecules or in nano-confined environments. As a result, their dynamics can differ significantly from those in bulk systems. In the first part of my talk, I will illustrate the unique dynamical signatures of cluster size and degree of confinement on simulated two-dimensional and pump-probe infrared spectra of hydrogen-bonded complexes dissolved in polar nanoclusters and in polar clusters confined in hydrophobic nano-sized cavities, which are absent in standard (one-dimensional) infrared absorption spectra. In the second part of my talk, I will discuss the results of molecular dynamics simulations which shed light on the mechanisms, energetics, and the role played by hydrogen bonding in the deprotonation and decomposition reactions of carbonic acid (key reactions in blood pH regulation, CO2 transport in biological systems, the global carbon cycle, etc.) in nano-sized water clusters.

Ken Cadien

Date and Time: January 31, 2014 at 12:00pm
Speaker: Dr. Ken CadienDepartment of Chemical and Materials Engineering
Title: "Atomic Layer Deposition and In-situ Diagnostics"

Abstract: Atomic layer deposition (ALD) is a powerful technique for depositing oxide , nitride and metal thin films in the nanoscale regime. Spectroscopic ellipsometry (SE) is a techniques that is used to measure the optical properties of thin films. The combination of ALD and in-situ SE permits a researcher to a more fundamental understanding on the processes that occur during film deposition. In this talk, the fundamentals of ALD and SE will be discussed, and several examples of the application of ALD and SE to real world problems. Examples to be covered at ALD growth of oxides on metal films, gate oxides for device applications, and nitrides for compound semiconductor applications.

Dan Sameoto

Date and Time:  November 8, 2013 at 12:00pm
Speaker: Dr. Dan Sameoto, Department of Mechanical Engineering
Title: "Bioinspired Micro and Nanofabrication - From Plastics to Products"

Abstract: Polymer based microfabrication is a growing sub-specialty of micro and nanofabrication. For the last decade important innovations in the field of bioinspired products, like superhydrophobic surfaces, iridescent materials and gecko-inspired adhesives have benefited greatly from the generally lower costs, novel fabrication techniques and durable designs that are possible through the use of polymer microfabrication.  This talk will cover the use of polymers and plastics in general for microfabrication of gecko-inspired adhesives, their current state of the art, and possible future uses in fields as broad as MEMS pick and place, sporting goods and space robotics.  The choice of appropriate polymers and fabrication techniques, along with the unique technical challenges when working with novel materials and composites will also be covered, as the possibilities of industrial nanofabrication with materials like Plexiglas®, polystyrene and epoxies should allow for these bioinspired products to be introduced using existing macroscale manufacturing processes.

John Veinot

Date and Time:  October 3, 2013 at 12:00pm
Speaker: Dr. John Veinot, Department of Chemistry
Title: "Does size really matter? Tuning the optical properties of semiconductor nanomaterials and other useful nanoscale musings"

Abstract: Silicon nanocrystals (SiNCs) offer many benefits over prototypical CdSe quantum dots including biocompatibility. Adding to their appeal, SiNCs are also compatible with standard electronics and communications platforms, some exhibit size dependent photoluminescence and evidence to date suggests stabilizing surface groups are not labile. Numerous innovative solution-, gas-, and solid-phase methods have been developed to realize size-controlled SiNC synthesis. All procedures afford SiNCs that appear seemingly identical. However, based upon SiNC optical response it is clear they are not. SiNCs prepared using high-temperature methods routinely exhibit photoluminescence agreeing with the effective mass approximation. SiNCs prepared via solution methods exhibit blue emission that is independent of particle size. Despite many creative proposals, a concrete explanation for this difference has eluded the nanomaterials community for no less than a decade. This apparent dichotomy brings into question our understanding of SiNC properties and potentially limits the full scope their applications. This presentation will introduce SiNCs and many of the standard literature procedures used for their preparation. Focus will then shift to oxide-embedded and surface functionalized freestanding SiNCs prepared using procedures developed in the Veinot Laboratory and our determination of the origin of the blue emission noted above. A detailed comparison of blue-emitting SiNCs synthesized by the Kauzlarich (UC Davis) and Tilley (Victoria University of Wellington) groups will also be described.

Kevin Beach

Date and Time:  April 5, 2013 at 12:00pm 
Speaker: Dr. Kevin Beach, Department of Physics
Title: "Silicon Nitride Nanostrings"

Abstract: An interesting class of resonator consists of thin silicon nitride strips, etched on the micron-scale and suspended between pure silicon anchor posts. High intrinsic tension, together with the long and thin geometry, causes these devices to behave like strings rather than beams. The quality factor (Q) of these so-called nanostrings is generally quite high, and they have the potential to be useful in various sensing applications. At room temperature, nanostrings are sensitive enough to exhibit substantial vibrational motion simply due to thermal agitation. Alternatively, they can be driven to large amplitude on a piezo stage. It turns out that careful characterization of the first few modes gives useful information about the dominant dissipation channel and may give clues as to how to engineer the devices to higher Q. With the addition of a gold overlayer, the nanostrings can be electrically actuated—bringing them a step closer to serving as a self-contained device.

Michael Serpe

Date and Time:  February 14, 2013 at 11:30am 
Speaker: Dr. Michael Serpe, Department of Chemistry
Title: "The Colorful World of Poly (N-isopropylacrylamide) Microgel-Based Etalons"

Abstract: Etalons are optical devices composed of two mirrors deposited on either side of a planar, dielectric material. Light entering the dielectric between the mirrors can constructively and destructively interfere, leading to specific wavelengths of light being reflected and transmitted. This affords a device with visual color. The group has demonstrated that color tunable etalons can be constructed using thermoresponsive poly (N-isopropylacrylamide)-based microgels as the dielectric layer. This presentation will detail our research efforts in this area with a focus on controlling the optical properties of the devices and how they can be used for sensing and biosensing applications.

Mike Fleischauer

Date and Time:  January 25, 2013 at 12:30pm 
Speaker: Dr. Mike Fleischauer, National Institute for Nanotechnology
Title: "Nanotechnology in Rechargeable Batteries"

Abstract: Rechargeable lithium-ion batteries are big business. Recent advances in battery charge storage capacity and wide scale implementation depend on nanotechnology. This talk will provide an overview of state of the art bulk and nanostructured lithium-ion electrode materials, and how electrode properties impact the performance of the overall electrochemical cell. Results on predicting and directly imaging nanoscale structure within bulk electrodes will also be provided.

Chris Le

Date and Time:  November 30, 2012 at 12:00pm 
Speaker: Dr. Chris Le, Department of Laboratory Medicine and Pathology - Department of Chemistry
Title: "Binding-Induced DNA Assembly"

Abstract: My research group is interested in developing bioanalytical techniques that enable studies of molecular interactions and detection of targets significant to environment and human health. One active area of research involves the detection of nucleic acids and proteins. This presentation will illustrate the principle of assembling DNA through affinity binding and highlight novel applications to the detection of proteins. Assays and sensors making use of DNA assembly share three main attractive features: (i) the detection of proteins can be accomplished by the detection of amplifiable DNA, thereby dramatically enhancing the sensitivity; (ii) assembly of DNA is triggered by affinity binding of two or more probes to a single target molecule, resulting in increased specificity; and (iii) the assay is conducted in solution with no need for separation, making it attractive for potential point-of-care applications. 
One example is the binding-induced DNA assembly that enables ultrasensitive detection of molecular targets and potential construction of unique nanostructures/nanoreactors. Using both theoretical treatment and experimental validation, we achieve rational designs of DNA motifs that are conjugated to specific affinity ligands. These motifs assemble to form a highly stable closed-loop structure only when a specific target triggers a binding event. This binding-induced assembly of the DNA motifs raises the melting temperature (Tm) of the hybrid by more than 30 OC compared to the Tm for the DNA self-assembly. The dramatic increase in stability of the binding-induced assembly facilitates easy discrimination of the target-specific assembly from the background. With diminished background, we are able to detect sub-zeptomol amount of specific proteins. The concept of binding-induced DNA assembly can be applied to other DNA motifs and nanomaterials functionalized with DNA. The principle and strategy could potentially be used to assemble unique nanostructures, construct nanoswitches, and build nanoreactors, by incorporating unique signaling and/or structural features into the probes and DNA motifs.