Research - Overview

While we have seen great advances in chemical/biological sensing, health screening, and diagnostics in recent years, there are still some great challenges that remain to be addressed.  The relevant antigen (target) concentration for various disease states often challenges the limits of detection of current technologies.  The complexity of real-world samples such as blood, urine, saliva or food makes the detection of a specific disease biomarker or pathogen challenging, requiring complex sample preparation procedures. Also, the success of a sensing technology will be impacted by cost and ease of deployment in non-standard settings such in third world areas or even for bedside diagnostics.  We seek to address these issues from four fronts:

  1. Biosensing: Development of novel assays and detection/characterization technologies

  2. Lab-on-a-Chip: Implementation of sample manipulation, separation and concentration platforms

  3. Science: Establishing a fundamental understanding of the science relevant to each sensing platforms

  4. Technology: Providing new quantitative measurement capabilities for conducting basic research in biology, chemistry and physics

Ongoing projects

Detecting molecular substructure using solid-state nanopore biosensors

Charged biomolecules such as DNA and proteins can be electrophoretically driven through nano-scale pores in insulating membranes. The resulting ionic current signatures yield information about molecular size, length, conformation and structure. Our research aims to leverage this ability for the detection of disease biomarkers, study molecular interactions and design novel biomolecular assays.

Scientist: Eric Beamish

Collaborator: Professor Tabard-Cossa

Integrated Nanopore Sensor in Three-Dimensional Microfluidic Devices for Single-Molecule Detection

Nanopore sensors are a relatively new technology capable of detection and analysis with single-molecule sensitivity. This work highlights the integration of solid-state nanopores within various microfluidic networks using controlled breakdown of a dielectric with the aim of enhancing the analytical capabilities required to analyse biomolecular samples.

Scientist: Dr. Ali Najafi Sohi, Radin Tahvildari

Collaborator: Professor Tabard-Cossa

Controlled encapsulation of Single cells into monodisperse picoliter drops

We have designed a microfluidic device capable of encapsulating individual or small groups of cells in agarose capsules at high-throughput. The device allows us to encapsulate therapeutic cells in a semi-automatic, efficient and reproducible manner while providing for precise control over their size and uniformity. We are developing various technologies to be integrated within our microdevice that will allow for increased throughput and cocoon sorting (increased occupancy). In addition, novel biomaterials (i.e. hydrogels) will be investigated to tune the capsules microenvironment to increase cell viability and control cell escape

Scientists: Dr. Ainara Benavente-Babace , Adefami Adeyemi, Rushi Panchal

Collaborators: Professor Harden , Dr. Stewart , Dr. Courtman, Dr. Darryl Davis

On-chip stretchable decive for morophological cell study

The cells composing the human body are evolving in a very dynamic environment in which the specific physical properties are central in the regulation of numerous cellular processes determining the cellular fate. Microfluidic devices are ideal platforms to mimic a variety of in vivo mechanical cues and study their effects on cell behaviour. Recent research has shown for example that cells are able to sense and respond to subtle cues such as the strain gradient. These microdevices can also be used to study more complex biological systems, such as the evolution of the earliest stage of cancer in a highly dynamic environment.

Scientist: Sophie Chagnon-Lessard

Collaborator: Professor Pelling

Completed projects

Single cell studies with on-chip microfluidic volume sensors

Microfluidic impedance-based single-cell volume sensing is a powerful technique capable of sizing micrometer-sized biotargets, such as bacteria and mammalian cells. This technology relies on the Coulter principle, whereby transiting microtargets flow through an electric field and displace their own volume of ions, leading to a precise measurement of their size. We have published several articles in Biomicrofluidics , Microelectronic Engineering and Lab on a Chip detailing efforts to render such technology. Interests include cell sorting with pneumatic valves and long term volume monitoring of cells in a pressure-driven trap.

Scientist: Wenyang Jing and Jason Riordon

Sort particles and cells based on high-resolution volume measurements

We demonstrated a microfluidic device that integrates high-sensitivity volume sensing with active pressure-driven flow sorting. Label-free size-based sorting of microparticles and cells is achieved using hydrodynamic flow focusing combined with a resistive pulse sensor with tunable sensitivity that utilizes the Coulter principle. This integrated on-chip sizing and sorting method is ideal for sorting small numbers of particles/cells at very high resolution.

Scientists: Jason Riordon

An investigation on transition modes of Gravitational field-flow fractionation in micro fluidic channels

Field-Flow Fractionation (FFF) is a broad class of separation techniques designed to separate everything from colloids to macromolecules to cells. Gravitational field-flow fractionation (Gr-FFF) uses the Earth’s gravity as the external field and is relatively simple in principle and operation. In this research, we investigated on transition between modes that happen based on size of micro particles.

Scientists: Radin Tahvildari and Tyler Shendruk

Collaborator: Professor Slater

Control the size and noise of solid-state nanopores using high electric fields

A methodology was presented to prepare solid state nanopores that provides in situ control of size with sub-nanometer precision while simultaneously reducing electrical noise. The approach enables the recycling of previously used and clogged nanopores, as the process removes parasitic debris and/or physisorbed molecules .

Scientists: Eric Beamish

Collaborator: Professor Tabard-Cossa