PI: Dr. Sayfe Kiaei IUCRC Center: Connection One Students: Patricia Markison, Fernando Moraila Summary of Proposed Work 1) Wireless Stethoscope: This project involves the development of a contactless method for monitoring human vital signs, an instrument which can accurately measure heart and respiration rate of a subject under observation from a distance of a few feet. The instrument transmits low power Radio waves in the direction of the subject under observation and senses the reflected waves which carry the signature of the heart and respiration rate and from these the vital signs are estimated. The motion of the heart and chest wall induce a frequency Doppler shift on the incident radio waves, hence by accurately measuring this small Doppler shift on the received signal the respiration rate and heart beat can be remotely measured. The system comprises of analog and digital modules. The analog module consists of an analog front end, the radio transmitter and receiver which contain the RF analog circuits which operate in order of Giga-Hertz. Followed by an analog back end which operates in order of few Kilo-Hertz, this module interfaces the digital and analog system via Digital to Analog (DAC) and Analog to Digital Convertors (ADC). This project will be designed and simulated in Cadence to be fabricated and tested for further use. 2) Digital Power Regulator: The second project involves the development of a completely digital low-dropout regulator. Most regulators have parts that are digital, such as shift registers, counters, etc. and others that are analog, commonly the comparator, VCO, integrator, etc. There are some issues with having analog parts in the regulator, for instance response time, quiescent current, and issues with altering the process technology and thus creating a fully digital LDO regulator becomes advantageous. This LDO regulator would utilize voltage to change the frequency of a ring oscillator. This frequency would be compared to a reference frequency through a
This project seeks to design and implement a high-Q MEMS (Micro-Electro- Mechanical-System) FBAR (Film Bulk Acoustic Resonator) in a liquid environment using an aluminum nitride (AlN) thin film. The AlN film serves as a piezoelectric element to produce a longitudinal mode FBAR. Reactive magnetron sputtering is used to grow the AlN film onto ZrN/AlN bilayers on a silicon nitride film. The thickness and the quality of the AlN film primarily determine the resonant frequency and inherent Q of the FBAR, respectively. The AlN film is sandwiched by two metal electrodes to form the FBAR.. The FBAR has an integrated microfluidic channel directly on top of its top electrode, which has molecular probes to capture target molecules. The effective mass of the FBAR changes to shift its resonant frequency upon the capture of the target molecules. Unlike conventional FBARs in a liquid environment, the proposed FBAR is integrated with the microfluidic channel, which reduces the travel path of the acoustic signal generated by the FBAR, and consequently improves the Q and detection limit.
This proposal is to renew the Center NSF support for Phase III from 2012-2017. The focus of the Connection One (www.connectionone.org) consortium is on Communication Circuits and Systems for the next generation of wireless, RF, and Integrated Sensors on a Chip.
|Effective start/end date||9/1/07 → 8/31/14|
- National Science Foundation (NSF): $500,000.00
Variable frequency oscillators