A5027760538- Microfluidic and Bio-sensing Technologies
- 3D Printing in Biomedical Research
- Cellular Mechanics and Interactions
- Microfluidic and Capillary Electrophoresis Applications
- Nanopore and Nanochannel Transport Studies
- Mechanical and Optical Resonators
- Force Microscopy Techniques and Applications
- Analytical Chemistry and Sensors
- Electrospun Nanofibers in Biomedical Applications
- Extracellular vesicles in disease
- Tissue Engineering and Regenerative Medicine
- Microtubule and mitosis dynamics
- Spaceflight effects on biology
- Advanced biosensing and bioanalysis techniques
- RNA Interference and Gene Delivery
- Advanced MEMS and NEMS Technologies
- Photonic Crystal and Fiber Optics
- Innovative Microfluidic and Catalytic Techniques Innovation
- Bone Tissue Engineering Materials
- Spectroscopy Techniques in Biomedical and Chemical Research
- Advanced Fiber Optic Sensors
- Neuroscience and Neural Engineering
- Acoustic Wave Resonator Technologies
- MicroRNA in disease regulation
- Advanced Sensor and Energy Harvesting Materials
Carleton University
2013-2024
University of Ottawa
2015-2024
Institute for Biomedical Engineering
2015-2020
Ottawa University
2019
In-Q-Tel
2016-2017
FX Palo Alto Laboratory
2016
University of Toronto
2010
Massachusetts Institute of Technology
2006-2010
McGill University
2001-2007
Columbia University
2006
We demonstrate the measurement of mass, density, and size cells nanoparticles using suspended microchannel resonators. The masses individual particles are quantified as transient frequency shifts, while transit a microfluidic channel embedded in resonating cantilever. Mass histograms resulting from these data reveal distribution population heterogeneously sized particles. Particle density is inferred measurements made different carrier fluids since shift for particle proportional to mass...
The surface stress induced during the formation of alkanethiol self-assembled monolayers (SAMs) on gold from vapor phase was measured using a micromechanical cantilever-based chemical sensor. Simultaneous in situ thickness measurements were carried out ellipsometry. Ex scanning tunneling microscopy performed air to ascertain final monolayer structure. evolution coverage-dependent structural transitions reveals features not apparent average ellipsometric measurements. These results show that...
Many interactions drive the adsorption of molecules on surfaces, all which can result in a measurable change surface stress. This article compares contributions various possible to overall induced stress for cantilever-based sensing applications. The resulting from adsorption-induced changes electronic density underlying is up 2–4 orders magnitude larger than that intermolecular electrostatic or Lennard-Jones interactions. We reveal associated with formation high quality alkanethiol...
We present a methodology for preparing silicon nitride nanopores that provides in situ control of size with sub-nanometer precision while simultaneously reducing electrical noise by up to three orders magnitude through the cyclic application high electric fields an aqueous environment. Over 90% treated this technique display desirable characteristics and readily exhibit translocation double-stranded DNA molecules. Furthermore, previously used degraded properties can be rejuvenated further...
Functional low-noise nanopore arrays are fabricated by controlled dielectric breakdown in solid-state membranes integrated within microfluidic devices.
Abstract When stretched, cells cultured on 2D substrates share a universal softening and fluidization response that arises from poorly understood remodeling of well-conserved cytoskeletal elements. It is known, however, the structure distribution cytoskeleton profoundly influenced by dimensionality cell’s environment. Therefore, in this study we aimed to determine whether 3D matrix behavior link it remodeling. To achieve this, developed high-throughput approach measure dynamic mechanical...
A multi-layered polydimethylsiloxane microfluidic device with an integrated suspended membrane has been fabricated that allows dynamic and multi-axial mechanical deformation simultaneous live-cell microscopy imaging. The transparent membrane's strain field can be controlled independently along two orthogonal directions. Human foreskin fibroblasts were immobilized on the surface stretched directions sequentially while performing Cyclic of cells induced a reversible reorientation perpendicular...
A method for calculating the surface stress associated with deflection of a micromechanical cantilever is presented. This overcomes some limitations Stoney’s formula by circumventing need to know cantilever’s Young’s modulus, which can have high level uncertainty, especially silicon nitride cantilevers. The calculated using readily measurable properties, such as its geometry, spring constant, and deflection. applicable both rectangular triangular calibration measurement also accurate within 4%–7%.
The surface stress response of micromechanical cantilever-based sensors was studied as a function the morphology, adhesion, and cleanliness gold sensing surface. Two model systems were investigated: adsorption alkanethiol self-assembled monolayers at gas−solid interface potential-controlled anions liquid−solid interface. potential-induced stress, on smooth continuous polycrystalline Au(111)-textured microcantilever in 0.1 M HClO4, is excellent agreement with macroscopic Au(111)...
We report that a single hollow core photonic crystal fiber (HC-PCF) can be used for repetitive characterization of multiple samples by Raman spectroscopy. This was achieved integrating the HC-PCF to differential pressure system allowed effective filling, draining and re-filling into under identical optical conditions. Consequently, high-quality reliable spectral data could obtained which were suitable multivariate analysis (partial least squares). With present scheme, we able accurately...
On-chip microvalves regulate electrical and fluidic access to an array of nanopores integrated within microfluidic networks. This configuration allows for on-chip sequestration biomolecular samples in various flow channels analysis by independent nanopores. Please note: The publisher is not responsible the content or functionality any supporting information supplied authors. Any queries (other than missing content) should be directed corresponding author article.
The identification of molecular tags along nucleic acid sequences has many potential applications in bionanotechnology, disease biomarker detection, and DNA sequencing. An attractive approach to this end is the use solid-state nanopores, which can electrically detect substructure be integrated into portable lab-on-a-chip sensors. We present here a origami-based assembly nanopores are capable differentiating 165 bp scaffolds containing zero, one, two dsDNA protrusions. This highly scalable...
Sensing performance of solid-state nanopores is limited by the fast kinetics small molecular targets. To address this challenge, we translate presence a target to large conformational change long polymer. In work, explore for sensing states nanoswitches assembled using principles DNA origami. These programmable single-molecule switches show great potential in diagnostics and long-term information storage. We investigate translocation properties linear looped nanoswitch topologies fabricated...
A biomimetic microdevice reveals that strain gradients act as potent physical cues which guide the long-range organization of cells.
Integrating nanopore sensors within microfluidic architectures is key to providing advanced sample processing capabilities upstream of the biosensor. When confined in a microchannel, capture and translocation characteristics are altered when subjected cross-flow, affecting sensor performance. Here, we study rate 1–5 kbp double-stranded DNA molecules through solid-state nanopores presence tangential fluid flow over aperture. Experiments reveal trend increased with reaching 5-fold enhancement...
Developing methods to study tissue mechanics and myofibroblast activation may lead new targets for therapeutic treatments that are urgently needed fibrotic disease. Microtissue arrays a promising approach conduct relatively high-throughput research into fibrosis as they recapitulate key biomechanical aspects of the disease through relevant 3D extracellular environment. In early work, our group developed device called MVAS-force stretch microtissues while enabling simultaneous assessment...
We measure the surface stress induced by electrochemical transformations of a thin conducting polymer film. One side micromechanical cantilever-based sensor is covered with an electropolymerized dodecyl benzenesulfonate-doped polypyrrole (PPyDBS) The microcantilever serves as both working electrode (in conventional three-electrode cell configuration) and mechanical transducer for simultaneous, in situ, real-time measurements current interfacial changes. A compressive change about −2 N/m...
We present a robust and simple method for direct, label-free PCR product quantification using an integrated microelectronic sensor. The field-effect sensor can sequentially detect the intrinsic charge of multiple unprocessed products does not require sample processing or additional reagents in mixture. measures nucleic acid concentration relevant range specifically detects over such as Taq polymerase nucleotide monomers. monitor at various stages generate readout that resembles real-time...
Most atomic force microscopes and cantilever-based sensors use an optical laser beam detection system to monitor cantilever deflections. We have developed a working model that accurately describes the way in which position sensitive photodetector interprets deflection of these instruments. This exactly predicts numerical relationship between measured signal actual deflection. In addition, is used optimize geometry such systems, greatly simplifies any instrument uses system.