Miniature Piezoelectric Shaker Mechanism for Autonomous Distribution ofUnconsolidated Sample to Instrument Cells

摘要

To perform in-situ measurements on Mars or other planetary bodies many instruments require powder producedusing some sampling technique (drilling/coring) or sample processing technique (core crushing) to be placed inmeasurement cells. This usually requires filling a small sample cell using an inlet funnel. In order to minimize crosscontamination with future samples and ensure the sample is transferred from the funnel to the test cell with minimalresidual powder the funnel is shaken. The shaking assists gravity by fluidizing the powder and restoring flow of thematerial. In order to counter cross contamination or potential clogging due to settling during autonomous handling apiezoelectric shaking mechanism was designed for the deposition of sample fines in instrument inlet funnels. Thisdevice was designed to be lightweight, consume low power and demonstrated to be a resilient solid state actuator thatcan be mechanically and electrically tuned to shake the inlet funnel. In the final design configuration tested undernominal Mars Ambient conditions the funnel mechanism is driven by three symmetrically mounted piezoelectric flexureactuators that are out of the funnel support load path. The frequency of the actuation can be electrically controlled andmonitored and mechanically tuned by the addition of tuning mass on the free end of the actuator. Unlike conventionalelectromagnetic motors these devices are solid state and can be designed with no macroscopically moving parts. Thispaper will discuss the design and testing results of these shaking mechanisms.