Claims
- 1. A sensor for sensing velocity of ultrasonic waves in fluids in microchannels formed in a microfluidic device comprising:a capacitive micromachined ultrasonic transducer integrated in one wall of the channel, a pulser for applying electrical pulses to said ultrasonic transducer to transmit ultrasonic waves which travel through the fluid in said channel and reflect from the opposite wall of said channel, said transducer adapted to receive ultrasonic waves reflected from the opposite wall and generate an output signal, an analog to digital converter connected to received said output signals and provide a representative digital output, and a processor configured to receive said digital output and determine the time of travel of ultrasonic waves through the fluid and to determine from the time of travel and the distance the ultrasonic waves travel through the fluid the velocity of the ultrasonic waves in the fluid.
- 2. A sensor as in claim 1 in which the processor includes a look-up table showing the velocity of the fluid as a function of temperature whereby the processor compares the velocity of the ultrasonic waves in the fluid to the look-up table to provide an output representative of temperature.
- 3. A sensor for sensing velocity of sound in fluids in microchannels formed in a microfluidic device comprising:a capacitive micromachined ultrasonic transducer integrated into one wall of said microchannel; a pulser for applying electrical pulses to said ultrasonic transducer to transmit ultrasonic waves which travel through the fluid in said channel and reflect from the opposite wall of said channel, said transducer adapted to receive ultrasonic waves and generate an output signal; and a processor circuit configured to receive the electrical pulses and the output signal and determine the velocity of the ultrasonic waves by measuring the phase difference between the transmitted ultrasonic waves and the received ultrasonic waves.
- 4. A sensor as in claim 3 in which the processor includes a look-up table showing the velocity of the fluid as a function of temperature whereby the processor compares the velocity of the ultrasonic waves in the fluid to that in the look-up table to provide an output representative of temperature.
RELATED APPLICATIONS
This application claims priority to Provisional Application Ser. No. 60/309,245 filed Jul. 31, 2001.
GOVERNMENT SUPPORT
This invention was made with Government support under Contract No. N 66001-00-C-8077 awarded by the Navy. The Government has certain rights in this invention.
US Referenced Citations (8)
Number |
Name |
Date |
Kind |
4655992 |
McKnight et al. |
Apr 1987 |
A |
5360268 |
Hayashi et al. |
Nov 1994 |
A |
5619476 |
Haller et al. |
Apr 1997 |
A |
5870351 |
Ladabaum et al. |
Feb 1999 |
A |
5894452 |
Ladabaum et al. |
Apr 1999 |
A |
6026688 |
Khuri-Yakub et al. |
Feb 2000 |
A |
6151558 |
Conant et al. |
Nov 2000 |
A |
6250161 |
Khuri-Yakub et al. |
Jun 2001 |
B1 |
Non-Patent Literature Citations (1)
Entry |
H. Jagannathan et al., “Micro-Fluidic Channels with Integrated Ultrasonic Transducers,” 2001 IEEE Ultrasonic Symposium, Oct. 7-10, 2001, pp. 859-862. |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/309245 |
Jul 2001 |
US |