Home Research Focus Publications 2007 – 1999 - 2006 Personnel Activities	Publications 1999 - 2006 Kefeng Zeng, Keat G. Ong, Xiping Yang, Craig A. Grimes, "Board level integrated microsystern design and associated technique for impedance analysis of resonator sensors, "Sensor Letters, vol. 4(4), pp. 388-397, 2006. Oomman K. Varghese, Xiping Yang, James Kendig, Maggie Paulose, Kefeng Zeng, Charles Palmer, Keat Ghee Ong, Craig A. Grimes, "A transcutaneous hydrogen sensor: from design to application," Sensor Letters, vol. 4, pp. 120–128, 2006. Keat G. Ong, Kefeng Zeng, Xiping Yang, Karthik Shankar, Chuanmin Ruan, Craig A. Grimes, "Quantification of multiple bioagents with wireless, remote-query magnetoelastic micro-sensors," IEEE Sensors Journal, vol. 6, no. 3, pp. 514-523, 2006. Maggie Paulose, Oomman K. Varghese, Gopal K. Mor, Craig A. Grimes, Keat G. Ong, "Unprecedented ultra-high hydrogen gas sensitivity in undoped titania nanotubes," Nanotechnology, vol. 17, pp. 398–402, 2006. Keat G. Ong, Joshua M. Leland, Kefeng Zeng, Gary Barrett, Mohammed Zourob, Craig A. Grimes, “A rapid highly-sensitive endotoxin detection system,” Biosensors and Bioelectronics, vol. 21, 2270-2274, 2006. Gopal K. Mor. Oomman K. Varghese, Maggie Paulose, Keat G. Ong, Craig A. Grimes, “Fabrication of hydrogen sensors with transparent titanium oxide nanotube-array thin films as sensing elements,” Thin Solid Films, vol. 496, pp. 42-48, 2006. Keat Ghee Ong, Oomman K. Varghese, Gopal K. Mor, Craig A. Grimes, “Numerical Simulation of Light Propagation Through Highly-Ordered Titania Nanotube Arrays: Dimension Optimization for Improved Photoabsorption,” Journal of Nanoscience and Nanotechnology, vol. 5, no. 11, pp. 1801-1808, 2005. Keat Ghee Ong, Xiping Yang, Kefeng Zeng, Craig A. Grimes, “Magnetoelastic sensors for biomedical monitoring,” Sensor Letters, vol. 3, no. 2, pp. 108-116, 2005. Kefeng Zeng, Maggie Paulose, Keat G. Ong, Craig A. Grimes, “Frequency-domain characterization of magnetoelastic sensors: a microcontroller-based instrument for spectrum analysis using a threshold-crossing counting technique,” Sensors and Actuators A, vol. 121, pp. 66-71, 2005. Sriram N. Kizhakkemadam, Keat G. Ong, Maggie Paulose, Craig A. Grimes, “An active circuit for wireless broadcast of sensor information: Application to humidity monitoring,” Sensor Letters, vol. 3-4, pp. 175-178, 2004. Chuanmin Ruan, Oomman K. Varghese, Craig A. Grimes, Kefeng Zeng, Xipng Yang, Niloy Mukherjee, Keat G. Ong, “A magnetoelastic ricin immunosensor,” Sensor Letters, vol. 2, pp. 134-142, 2004. K. G. Ong, X. Yang, N. Mukherjee, H. Wang, S. Surender, C. A. Grimes, “A Wireless sensor network for long-term monitoring of aquatic environments: Design and implementation,” Sensor Letters, vol. 2, no. 1, pp. 48-57, 2004. C. Ruan, K. G. Ong, C. S. Mungle, M. Paulose, N. J. Nickl, C. A. Grimes, “A wireless pH sensor based on the use of salt-independent micro-scale polymer spheres,” Sensors and Actuators B, vol. 96, pp. 61-69, 2003. Oomman K. Varghese, Dawei Gong, Maggie Paulose, Keat G. Ong, Craig A. Grimes, “Hydrogen sensing using titania nanotubes,” Sensors and Actuators B, vol. 93, pp. 338-344, 2003. Keat G. Ong, Craig A. Grimes, “Magnetically-soft higher-order harmonic stress and temperature sensors,” IEEE Transactions on Magnetics, vol. 39, no. 5, pp. 3319-3321, 2003. Keat G. Ong, Casey S. Mungle, Craig A. Grimes, “Control of a magnetoelastic sensor temperature response by magnetic field tuning,” IEEE Transactions on Magnetics, vol. 39, no. 5, pp. 3414-3416, 2003. Craig A. Grimes, Keat G. Ong, Oomman K. Varghese, Xiping Yang, G. Mor, Maggie Paulose, Elizabeth C. Dickey, Chuanmin Ruan, Michael V. Pishko, James W. Kendig and Andrew J. Mason, “A sentinel sensor network for hydrogen sensing,” Sensors, vol. 3, pp. 69-82, 2003. Oomman K. Varghese, Dawei Gong, Maggie Paulose, Keat G. Ong, Elizabeth C. Dickey, Craig A. Grimes, “Extreme changes in the electrical resistance of titania nanotubes with hydrogen exposure”, Advanced Materials, vol. 15, no 7-8, pp. 624-627, 2003. Oomman K. Varghese, Dawei Gong, William R. Dreschel, Keat G. Ong, and Craig A. Grimes, “Ammonia detection using nanoporous alumina resistive and surface acoustic wave sensors,” Sensors and Actuators B, vol. 94, pp. 27-35, 2003. Keat G. Ong, William R. Dreschel, Craig A. Grimes, “Detection of human respiration using square-wave modulated electromagnetic impulses,” Microwave and Optical Technology Letters, vol. 36, no. 5, pp. 339-343, 2003. Keat G. Ong, Maggie Paulose, Craig A. Grimes, “A wireless, passive, magnetically-soft harmonic sensor for monitoring sodium hypochlorite concentrations in water,” Sensors, vol. 3, pp. 11-18, 2003. Xiping Yang, Keat G. Ong, William R. Dreschel, Kefeng Zeng, Casey S. Mungle, Craig A. Grimes, “Design of a wireless sensor network for long term, in situ monitoring in an aqueous environment,” Sensors, vol. 2, pp. 455-472, 2002. K. Zeng, K. G. Ong, C. S. Mungle, C. A. Grimes, “Time domain characterization of oscillating sensors: application of frequency counting to resonance frequency determination,” Review of Scientific Instruments, vol. 73, no. 12, pp. 4375-4380, 2002. K. G. Ong, J. S. Bitler, C. A. Grimes, L. G. Puckett, L. G. Bachas, “Remote query resonant-circuit sensors for monitoring of bacteria growth: application to food quality control,” Sensors, vol. 2, pp. 219-232, 2002. C. A. Grimes, C. S. Mungle, K. Zeng, M. K. Jain, W. R. Dreschel, M. Paulose, K. G. Ong, “(Invited paper) Wireless magnetoelastic resonance sensors: a critical review,” Sensors, vol. 2, pp. 294-313, 2002. K. G. Ong, C. A. Grimes, “Tracking the harmonic response of magnetically-soft sensors for wireless temperature, stress, and corrosive monitoring,” Sensors and Actuators A, vol. 101, pp.49-61, 2002. O. K. Varghese, D. Gong, M. Paulose, K. G. Ong, C. A. Grimes, E. C. Dickey, “Highly ordered nanoporous alumina films: Effect of pore size and uniformity on sensing performance.” J. Mater. Res., vol. 17, no. 5, pp. 1162-1171, 2002. E. C. Dickey, O. K. Varghese, K. G. Ong, D. Gong, M. Paulose, C. A. Grimes, “Room temperature ammonia and humidity sensing using highly ordered nanoporous alumina films,” Sensors, vol. 2, pp. 91-111, 2002. K. G. Ong, K. Zeng, C. A. Grimes, “A wireless, passive carbon nanotube-based gas sensor,” IEEE Sensors Journal, vol. 2, no. 2, pp. 82-88, 2002. K. G. Ong, D. M. Grimes, C. A. Grimes, “Higher-order harmonics of a magnetically-soft sensor: Application to remote query temperature measurement,” Applied Physic Letters, vol. 80, no. 20, pp. 3856-3858, 2002. K. G. Ong and C. A. Grimes, “A carbon nanotube-based sensor for CO2 monitoring,” Sensors, vol. 1, pp. 193-205, 2001. K. G. Ong, M. Paulose, M. K. Jain, D. Gong, O. K. Varghese, C. Mungle, and C. A. Grimes, “Magnetism-based remote query glucose sensors,” Sensors, vol. 1, pp. 138-147, 2001. O. K. Varghese, P. D. Kichambare, D. Gong, K. G. Ong, E. C. Dickey, C. A. Grimes, “Gas sensing characteristic of multi-wall carbon nanotubes,” Sensors and Actuators B, vol. 81, pp. 32-41, 2001. E. C. Dickey, C. A. Grimes, M. K. Jain, K. G. Ong, D. Qian, P. D. Kichambare, R. Andrews, D. Jacques, “Visible photoluminescence from ruthenium-containing multiwall carbon nanotubes,” Applied Physics Letters, vol. 79, no. 24, pp. 4022-4024, 2001. C. A. Grimes, E. C. Dickey, C. Mungle, K. G. Ong, D. Qian.  “Effect of purification of the electrical conductivity and complex permittivity of multiwall carbon nanotubes,” Journal of Applied Physics, vol. 90, no. 8, pp. 4134-4137, 2001. K. G. Ong, C. A. Grimes, C. L. Robbins, R. S. Singh, “Design and application of wireless, passive, resonant-circuit environmental monitoring sensor,” Sensors and Actuators A, vol. 93, pp. 33-43, 2001. K. G. Ong, R. S. Singh, J. Wang, L. G. Bachas, C. A. Grimes, “Monitoring of bacteria growth using a wireless, remote query resonant-circuit sensor: application to environmental sensing,” Biosensors and Bioelectronics, vol. 16, pp. 305-312, 2001. M. K. Jain, S. Schmidt, K. G. Ong, Casey Mungle, C. A. Grimes, “Magnetoacoustic remote query temperature and humidity sensors,” Journal of Smart Materials and Structures, vol. 9, pp. 502-510, 2000. C. A. Grimes, G. Liu, D. M. Grimes, K. G. Ong, “Characterization of a wide-band low Q, electrically-small antenna,” Microwave and Optical Technology Letters, vol. 27, pp. 53-58, 2000. K. G. Ong, C. A. Grimes, “A resonant printed-circuit sensor for remote query monitoring of environmental parameters,” Journal of Smart Materials and Structures, vol. 9, pp. 421-428, 2000. Keat Ghee Ong, Craig A. Grimes, “A method for quantifying the higher-order modes radiated by an arbitrarily shaped antenna,” Microwave and Optical Technology Letters, vol. 24, no. 1, pp. 20-24, 2000. Craig A. Grimes, Keat Ghee Ong, “High frequency, small signal MH loops of ferromagnetic thin films,” Journal of Applied Physics, vol. 87, no. 9, pp. 5977-5979, 2000. C. A. Grimes, D. Kouzoudis, K. G. Ong, R. Crump, “Thin-film magnetoelastic microsensors for remote query biomedical monitoring,” Journal of Biomedical Microdevices, vol. 2, pp. 51-60, 2000. C. A. Grimes, P. G. Stoyanov, D. Kouzoudis and K. G. Ong, “Remote query pressure measurement using magnetoelastic sensors,” Review of Scientific Instruments, vol. 70, no. 12, pp. 4711-4714, 1999. C. A. Grimes, P. G. Stoyanov, Y. Liu, C. Tong, K. G. Ong, K. Loiselle, M. Shaw, S. Doherty and W. R. Seitz, “A magnetostatic-coupling based remote query sensor for environmental monitoring,” Journal of Physics D: Applied Physics, vol. 32, pp. 1329-1335, 1999. Gang Liu, Craig A. Grimes, Keat Ghee Ong, “A method for FDTD computation of field values at spherical coordinate singularity points applied to antennas,” Microwave and Optical Technology Letters, vol. 20, no. 6, pp. 367-369, 1999. C. A. Grimes, Keat Ghee Ong, K. Loiselle, P. G. Stoyanov, D. Kouzoudis, Y. Liu, C. Tong, F. Tefiku, “Magnetoelastic sensors for remote query environmental monitoring,” Journal of Smart Materials and Structures, vol. 70, no. 12, pp. 639-646, 1999. Gang Liu, Keat Ghee Ong, Craig A. Grimes, Dale M. Grimes, “Comparison of time and frequency domain numerical modeling of outbound and local power from two perpendicularly oriented, electrically small tm dipoles,” International J. Numerical Modeling, vol. 12, pp. 229-241, 1999.