Research interests: Imaging Devices, Micro/Nanodevices, MEMS; Nanosensors
As Canada Research Chair in Micro and Nanodevices, Professor John T.W. Yeow is developing nanodevices (machines that work on a molecular level) and highly selective sensors that will help create new medical instruments for diagnosing and treating disease.
Bringing together knowledge and technology from chemistry and from materials and chemical engineering labs, Yeow will design, develop, manufacture, and test a miniaturized catheter device for in vivo, or internal, body imaging. This device will allow physicians to examine small and previously unseen human cavities, and assist in the early detection of diseases such as cancer.
Yeow is also developing miniature radiation instruments and sensors for cancer treatment that will allow for a more focused, yet less invasive, delivery of radiation treatment, as well as real-time measurement of the delivered dose during radiation therapy.
Ultimately, Yeow’s research will improve patients’ quality-of-life through the early detection of disease and the development of more effective treatment. In this translational research, the technologies developed will find applications in areas beyond biomedical applications.
PhD, Mechanical and Industrial Engineering, University of Toronto
MASc, Mechanical and Industrial Engineering, University of Toronto
BASc, University of Toronto
Awards and Honours
|Year||Awards and Honours|
|2019||Waterloo Institute for Nanotechnology Research Leaders Award|
Ontario’s Volunteer Service Award
|2019||Fellow, Canadian Academy of Engineering|
|2017/2018||IEEE Nanotechnology Technical Council Distinguished Lecturer|
|2016||Engineering Excellence Medal, PEO|
|2015||Fellow, The Engineering Institute of Canada|
Excellent Paper Award, IEEE International Conference on Nanotechnology
|2011||2nd place at the Global Nano Innovation Challenge Contest, Taiwan|
|2009/2014||Canada Research Chair in Micro/Nanodevices|
|2009/2014||NSERC Discovery Accelerator Supplements (DAS)|
|2008||Young Engineering Award, PEO|
Micro-/Nano-Electro Mechanical Systems
Micro/Nanoelectromechanical Systems (MEMS/NEMS) provide the advantages of small size, low cost, low power consumption, low mass, high reliability, and low maintenance on both the system as well as the component levels. My research interests are to develop and fabricate mechanical machines that are integrated with microelectronics at the micron scale. New device concepts include but are not limited to: the integration of micro-optics components, miniature signal processing devices, biomedical/genome processing devices, miniature electromechanical wireless components (filters, mixers, antennas), miniature opto-electromechanical devices (optical cross connect, optical relays, optical multiplexers, deformable optics), miniature biosensors and environmental sensors, and microfluidics devices. Issues such as self-testing, self-assembly, and automated packaging will be explored.
Like the Integrated Circuits (IC) fabrication, the fabrication process of MEMS is inherently planar. Three-dimensional (3-D) mechanical structures are built by the successive deposition and etching of structural and sacrificial layers of silicon-based materials in the same plane. Therefore, only simple in-plane structures can be constructed. The planar fabrication process limits the designs, functionality, and applications of current MEMS devices. Therefore, the ability to assemble micro parts by robotic micromanipulators would have serious implications. MEMS components such as out-of-plane gears, actuators, cantilevers, sensors, and end-effectors can be assembled. In the world with micro-assembly, micro parts are no longer restricted to 2 or 3 Degree-of-Freedom (DoF) motion. Multiple DoF micro components will not only enhance the performance and capability of MEMS, but also create new market for the technology.
Nanodevices for Biomedical Applications
On a smaller scale, the potential applications of Carbon Nanotubes (CNT) for biomedical instruments are limitless. CNT exhibit unique properties that include extremely high mechanical strength, high thermal conductivity, excellent chemical and thermal stability. My nanotechnology research thrust will focus on developing novel designs and fabrication concepts based on CNT/nanotechnology for next-generation instruments. The ultimate goal of the research is to realize fully functioning performance-enhanced biomedical nanodevices for clinical deployment.
- MEMS optical scanner for endoscopic optical coherence tomographic imaging
- Micromirror devices for genetic microarray reading and tissue imaging
- Robotics for micromanipulations of MEMS components
- Carbon nanotube-based sensors for biomedical applications
- Lab-on-a-chip designs
Recent publications include:
M. Zhang*, D. Ban, C. Xu**, J.T.W. Yeow, “Large-area and Broadband Thermoelectric Infrared Detection in A Carbon Nanotube Black-body Absorber,” ACS Nano, vol. 13, no. 11, pp. 13285-13292
J. Chan*, Z. Zheng*, K. Bell**, M. Le**, P.H. Reza, J.T.W. Yeow, “Photoacoustic Imaging with Capacitive Micromachined Ultrasound Transducers: Principles and Developments,” Sensors, vol. 19, no. 16, 3617, 2019
M. Zhang*, J.T.W. Yeow, “A flexible, scalable, and self-powered mid-infrared detector based on transparent PEDOT: PSS/graphene composite,” Carbon, vol. 156, pp. 339-345, 2019
Z. Zheng*, Y. Yao, J.A. Liu*, Y. Sun*, J.T.W. Yeow, “ Highly sensitive CMUT-based humidity sensors built with nitride-to-oxide wafer bonding technology,” Sensors and Actuators B: Chemical, vol. 294, pp. 123-131, 2019
C. Chen*, Z. Wen, A. Wei, X. Xie, N. Zhai, X. Wei, M. Peng, Y. Liu, X. Sun, J.T.W. Yeow, “Self-powered on-line ion concentration monitor in water transportation driven by triboelectric nanogenerator,” Nano Energy, vol. 62, pp. 442-448, 2019
Z. Zheng*, Y. Yao, Y. Sun**, J.T.W. Yeow, “Development of a highly sensitive humidity sensor based on the capacitive micromachined ultrasonic transducer,” Sensors and Actuators B: Chemical, vol. 286, pp. 39-45, 2019
S. Chen, S. Nambiar, Z. Li, E. Osei, J. Darko, W. Zheng, Z.D. Sun, P. Liu, J.T.W. Yeow, “Bismuth oxide-based nanocomposite for high-energy electron radiation shielding,” Journal of Materials Science, vol. 54, no. 4, pp. 3023-3034, 2019
C. Samarasekera*, J.G.W. Sun*, Z. Zheng*, J.T.W. Yeow, “Trapping, separating, and palpating microbead clusters in droplets and flows using capacitive micromachined ultrasonic transducers (CMUTs),” Sensors and Actuators B: Chemical, vol. 276, pp. 481-488, 2018
M. Zhang, J.T.W. Yeow, “Flexible Polymer–Carbon Nanotube Composite with High-Response Stability for Wearable Thermal Imaging,” ACS applied materials & interfaces, vol. 10, no. 31, pp. 26604-26609, 2018
A.U. Alam, Y. Qin, S. Nambiar, J.T.W. Yeow, M.M.R. Howlader, N.X. Hu, M.J. Deen, “Polymers and organic materials-based pH sensors for healthcare applications,” Progress in Materials Science, 2018
Z. Zheng*, S. Na*, A.I.H. Chen*, Z.H. Li*, L.L.P. Wong**, Z. Sun, Y. Yao, P. Liu, J.T.W. Yeow, “Development of a Novel CMUT-Based Concentric Dual-Element Ultrasonic Transducer: Design, Fabrication, and Characterization,” IEEE Journal of Microelectromechanical Systems, vol. 27, no. 3, pp. 538-546, 2018
Y. Li*, Y. Sun**, D.A. Jaffray, J.T.W. Yeow, “A novel field emission microscopy method to study field emission characteristics of freestanding carbon nanotube array,” Nanotechnology, 2017
A.I.H. Chen*; L.L.P. Wong**, S. Na*, Z. Li*, M. Macecek, J.T.W. Yeow, "Fabrication of a Curved Row-Column Addressed Capacitive Micromachined Ultrasonic Transducer Array," IEEE Journal of Microelectromechanical Systems, vol. 25, no. 4, pp.675-682, 2016
Z. Li*, S. Chen*, S. Nambiar, Y. Sun**, M. Zhang, W. Zheng, J.T.W. Yeow, “PMMA/MWCNT nanocomposite for proton radiation shielding applications,” Nanotechnology, vol. 27 no. 23, 234001, 2016
Y. Sun*, D.A. Jaffray, J.T.W. Yeow, “Self-heating Schottky emission from a ballasted carbon nanotube array,” Carbon, vol. 58, pp. 87-91, 2013
Y. Sun*, D.A. Jaffray, J.T.W. Yeow, "The Design and Fabrication of Carbon Nanotube based Field Emission X-ray Cathode with Ballast Resistor," IEEE Transactions on Electron Devices, vol. 60, no. 1, pp. 464-470, 2013
Y. Sun*, J.T.W. Yeow, D.A. Jaffray, “Design and Fabrication of Carbon Nanotube Field Emission Cathode with Coaxial Gate and Ballast Resistor,” Small, vol. 9, no. 20, pp. 3385-3389, 2013
Y. Sun*, D.A. Jaffray, L.Y. Chen, J.T.W. Yeow, "Poly (methyl methacrylate) Thin Film based Field Emission Microscope," IEEE Transactions on Nanotechnology, vol. 11, no. 3, pp. 441-443, 2012
A. Logan*, J.T.W. Yeow, L. Wong*, A. Chen*, “A 32x32 Element Row-Column Addressed Capacitive Micromachined Ultrasonic Transducer,” IEEE Transaction of Ultrason., Ferroelect, Freq. Contr., vol. 58, no. 6, pp. 1266-1271, 2011
A. S. Logan*, J.T.W. Yeow, "Fabricating Capacitive Micromachined Ultrasonic Transducers with a Novel Silicon Nitride Based Wafer Bonding Process," IEEE Transaction of Ultrason., Ferroelect, Freq. Contr., vol. 56, no. 5, pp. 1074-1084, 2009
J.T.W., Yeow, V.X.D., Yang, A., Chahwan, M.L. Gordon, B., Qi, I.A., Vitkin, B., Wilson, A.A., Goldenberg, “Micromachined 2-D Scanner for 3-D Optical Coherence Tomography,” Sensors and Actuators, A: Physical, vol. 17, no. 2, pp. 331–340, Jan. 2005