Vipin
 Vipin Ayanoor-Vitikkate
Graduate Research Assistant
Mechanical Engineering Department,
Stanford University

Ph.D. (ME) Stanford University, 2004-Present
M.S. (ME) Stanford University, 2002-2004
B.Tech. (ME) Indian Institute of Technology Madras, Chennai, India, 1998-2002

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Office: 530-101 | Phone: (650) 804-0834 | Fax:(650) 723-7657 | Email: vipinav@stanford.edu 

Education

Ph.D. candidate, Stanford University, Mechanical Engineering (2004-Present)
M.S., Stanford University, Mechanical Engineering (2002-2004)
B.Tech., Indian Institute of Technology Madras (IIT-M), Chennai, Mechanical Engineering(1998-2002)

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Research Interests

MEMS and microsystems, mechatronics, Nano technology control systems, Bio-medical devices.

Research Advisor

Prof. Thomas W Kenny, Department of Mechanical Engineering

Research Projects

Wafer scale encapsulated MEMS Gyros

The goal of the present work is to fabricate a high sensitivity inertial sensor with a reasonably good bandwidth using the thin wafer scale encapsulation technique. Packaging is an important step towards commercialization of the device and we plan to use thin wafer scale encapsulation technique developed previously in our group to package these devices. The silicon micro machined gyroscope will be fabricated on SOI wafers using Bosch DRIE etching techniques, which has been previously demonstrated in the fabrication of accelerometers. The encapsulation of the device can be carried out using LTO or epitaxial sealing in order to provide a high vacuum inside the device chamber. The advantages offered by this technique are the reduction in area of the die and thus less silicon surface is wasted. In addition to this the encapsulation technique helps in creating a vacuum inside the micro device, which reduces the damping effects and hence increases the quality factor Q of the gyro thus increasing the sensitivity. The project is supported by Defence Science Organisation (DSO), Singapore.

Wafer scale encapsulated miniature MEMS piezoresistive accelerometers

MEMS accelerometers have been around since late 1970's. Efforts have been ongoing to reduce the size of MEMS accelerometers to a range where they can be used for various Bio-medical applications like measurement of heart wall or to characterize lumbar spinal manipulation. The same sensor can be used in cochlear and middle ear implant. Important criteria for using MEMS devices in sucg applications is reducing the size of the device. This has to be done by reducing the packaging material as the sensor element does not scale well with sensor parameters. The over all size of the MEMS accelerometer is reduced using wafer scale encapsulation process. In this method the device is sealed inside the wafer by deposition of a thin layer of epitaxial silicon.

High speed acoustic separation of particles in microchannel using ultrasound

A standing wave is generated in a microchannel containing particles suspended in a fluid resulting in the particles experiencing acoustic radiation pressure. Acoustic radiation pressure is used to collect all the particle in a micro channel at the node using standing waves.Depending on the density and compressibility of the medium and particle the particle can either be collected at the node or the anti-node. In order to seperate two particles in a fluid flow, it is necessary to exploit the differencein physical property between the two. Here we make use of difference in accoustic radiation felt by particles of different sizes in order to seperate them.In a standing wave the acoustic radiation pressure depends on volume of a sperical particle. This means that as long as other physical properties are similar larger particles will move towards the node faster.
(Advisor: Prof. Thomas W Kenny, Department of Mechanical Engineering)

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Publications

  1. Ayanoor-Vitikkate, V; Chen, K-L; Park, WT; Kenny TW; "Development of a process for wafer scale encapsulation of devices with very wide trenches". ASME IMECE 2006, Chicago (In print).

  2. Ayanoor-Vitikkate, V; Chen, K-L; Park, WT;Yama, G; Kenny TW; "Wafer Scale Encapsulation of wide Gaps using oxidation of sacrificial Beams". IEEE IEMT 2006, Petaling Jaya, Malaysia.

  3. Woo-Tae Park; Partridge, A.; Candler, RN; Ayanoor-Vitikkate, V.; Yama, G.; Lutz, M.; Kenny, TW "Encapsulated submillimeter piezoresistive accelerometers". Source: Journal of Microelectromechanical Systems; June 2006; v.15, no.3, p.507-514

  4. Li, Holden; Vitikkate, Vipin; Kenny, Thomas. "High speed particles separation using ultrasound for lab-on-chip application". Source: American Society of Mechanical Engineers, Micro-Electro Mechanical Systems Division, (Publications) MEMS; 2004; p.487-490

  5. Park, Woo-Tae; Candler, Rob N.; Ayanoor-Vitikkate, Vipin; Lutz, Markus; Partridge, Aaron; Yama, Gary; Kenny, Thomas W. "Fully encapsulated sub-millimeter accelerometers." Source: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS); 2005; p.347-350

  6. Li, Holden; Vitikkate, Vipin; Kenny, TW; "Study of high speed acoustic separation in micro channels using u-PIV." 8th International Conference on Miniaturized Systems for Chemistry and Life Sciences. Sept 26-30, 2004, Malmo, Sweden.

  7. Woo-Tae Park; O'Connor, KN; Mallon, JR, Jr.; Maetani, T.; Candler, RN; Ayanoor-Vitikkate V; Roberson, JB; Puria, S.; Kenny, TW "Sub-mm encapsulated accelerometers: a fully implantable sensor for cochlear implants." Source: TRANSDUCERS '05. The 13th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers, 5-9 June 2005, Seoul, South Korea; p.109-12 Vol. 1

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Affiliations

Product Realization Lab (PRL)
Stanford Nano Facility
Centre for Integrated Systems
Micro Structures & sensors Lab
Mechanical Engineering Department

Stanford

Last updated February 21, 2007