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Research Areas

Implantable Electrode, for collecting brain neural signals. Karen Cheung.

Circuits of the Future? Crossed single-walled carbon nanotubes. Dr. Alireza Nojeh.

Micromotors and Sensors: Mechanical parts are etched in silicon. Dr. Edmond Cretu.

Research in our group is in areas:

Research projects:

Plants capture photons very efficiently. Can we learn from them in making photovoltaic devices? We are investigating the use of photosynthetic protein complexes in solar cells, with the aim of creating very low cost solar cells.
Multiphoton microscopy (MPM) is a non-invasive, high-resolution imaging method for looking at thick biological tissues. We use a femtosecond laser to develop MPM systems which can acquire two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) simultaneously. The MPM system is used to image cells and extracellular matrix in turbid tissues.
Biocompatible coatings for implantable polymer-based multielectrode arrays
Compared to other patterning techniques, inkjet printing provides a very versatile and low cost microfabrication capability that can be used to implement organic electronic devices including printable sensors, transistors, LEDs, and photovoltaics. Inkjet technology can be used to pattern a variety of liquids including polymers, proteins, and various solvents. Inkjet patterns can be made on a variety of substrates and in 3D.
Optical coherence tomography (OCT) utilizes techniques such as interferometry and coherence gating to obtain high-resolution tissue images. We develop OCT systems for biomedical and industrial applications.
A significant challenge in research on nanostructures is the lack of sufficient control over the fabrication processes. Therefore, an important aspect of our research is the study of nanostructure fabrication processes with the goal of achieving higher levels of control and reproducibility.
While silicon microneedles (see picture) are effective for drug delivery, the associated fabrication process is rather expensive. We are developing new manufacturing processes for batch fabrication of inexpensive microneedles. These devices will be designed for drug delivery and biosensing.
By embedding low dimensional (0D, 1D, 2D) materials such as nanowires, nanotubes and quantum dots in polymers, we want improve the conversion efficiency and extend the use of solar energy, as a viable clean energy solution. Significant improvements in photocurrent and photoabsorption of polymers doped with carbon nanotubes are promising for nanocomposite solar cells.
Due to the large surface-to-volume ratio of nanostructures, they are excellent candidates for ultra-high-sensitivity detection of chemicals and biological molecules. Our objective is the sensitive detection of RNA using such structures, with the ultimate goal of single-RNA detection.
We are designing a Vertical-Cavity Surface-Emitting Laser (VCSEL) structure, containing a Sub-Wavelength Grating (SWG) and a Photonic Crystal (Phc) slab, either of which might replace one of the Distributed Bragg Reflectors (DBRs), using Finite-Difference Time-Domain (FDTD) and a transfer matrix method.
This project aims to develop micro-endoscopes for in vivo intra-luminal tissue imaging. The design will use state-of-the-art techniques such as photonic crystal fibers, micro-optics, and MEMS scanners. The micro-endoscopes will enable high resolution, multimodality imaging of subsurface structures and compositions of internal organs.
Contractile polymers are applied to the tips of neuro-vascular catheters in order to help them navigate through the complex blood vessels found in the brain.
Through collaboration with the BC Cancer Research Center, our optical imaging systems and endomicroscopes will be applied to study lung and skin cancers. In vivo optical imaging will help doctors to detect cancer in its early stage.
We are developing integrated microfluidic systems for the rapid and high-efficiency selection of nucleic acid aptamers.
We develop a new mechanism for changing the architecture of microfluidic channels during device operation. Two co-streaming fluids are separated through a temporal wall using targeted gel formation inside a microfluidic channel. We derive explanations for this mechanism including scaling arguments for the wall thickness.
Optical injection locking uses a second (master) laser to inject photons at a similar wavelength into the transmitter laser (termed follower or slave). Under certain conditions, the follower laser is locked in phase to the master, and the laser dynamics fundamentally change and can result in far better device performance.
A magnetically actuated MEMS scanner with a microfabricated ferromagnetic nickel platform and thermosetting polydimethylsiloxane (PDMS) microlens is demonstrated. The device is driven by an external AC magnetic field, eliminating chip circuitry and thermal deformation from joule heating. The resonant frequency of 215.2 Hz and scanning angle of 23 of the scanner have been demonstrated.
Silicon waveguides using SOI substrate allow for the fabrication of extremely compact photonic circuits based on standard CMOS processing. The goal of this project is to simulate, design and characterize several highly attractive optical functions and sub-systems in silicon photonics.
This research project aims to develop an implantable, biocompatible, optical glucose monitor, which would have a tremendous health-care benefit, providing an improved glucose-monitoring tool for diabetics. It is based on semiconductor laser sources (VCSELs) at the ideal wavelength for optical glucose sensing.