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Compact Sensitive Piezoelectric Mass Balance for Measurement of Unconsolidated Materials in SpaceIn many in-situ instruments information about the mass of the sample could aid in the interpretation of the data and portioning instruments might require an accurate sizing of the sample mass before dispensing the sample. In addition, on potential sample return missions a method to directly assess the captured sample size would be required to determine if the sampler could return or needs to continue attempting to acquire sample. In an effort to meet these requirements piezoelectric balances were developed using flextensional actuators which are capable of monitoring the mass using two methods. A piezoelectric balance could be used to measure mass directly by monitoring the voltage developed across the piezoelectric which is linear with force, or it could be used in resonance to produce a frequency change proportional to the mass change. In this case of the latter, the piezoelectric actuator/balance would be swept in frequency through its fundamental resonance. If a mass is added to the balance the resonance frequency would shift down proportionally to the mass. By monitoring the frequency shift the mass could be determined. This design would allow for two independent measurements of the mass. In microgravity environments spacecraft thrusters could be used to provide acceleration in order to produce the required force for the first technique or to bring the mass into contact with the balance in the second approach. In addition, the measuring actuators, if driven at higher voltages, could be used to fluidize the powder to aid sample movement. In this paper, we outline some of our design considerations and present the results of a few prototype balances that we have developed.
Document ID
20150008571
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Sherrit, Stewart
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Trebi-Ollennu, Ashitey
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Bonitz, Robert
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Bar-Cohen, Yoseph
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Yen, Jesse T.
(University of Southern California Pasadena, CA, United States)
Date Acquired
May 20, 2015
Publication Date
March 7, 2010
Subject Category
Lunar And Planetary Science And Exploration
Meeting Information
Meeting: SPIE Conference - Electroactive Polymer Actuators and Devices (EAPAD)
Location: San Diego, CA
Country: United States
Start Date: March 7, 2010
End Date: March 11, 2010
Sponsors: International Society for Optical Engineering
Distribution Limits
Public
Copyright
Other
Keywords
resonance
flextensional actuators

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