Mechanism for Particle Transport and Size Sorting via Low-Frequency Vibrations

There is a need for effective sample handling tools to deliver and sort particles for analytical instruments that are planned for use in future NASA missions. Specifically, a need exists for a compact mechanism that allows transporting and sieving particle sizes of powdered cuttings and soil grains that may be acquired by sampling tools such as a robotic scoop or drill. The required tool needs to be low mass and compact to operate from such platforms as a lander or rover. This technology also would be applicable to sample handling when transporting samples to analyzers and sorting particles by size

System for Packaging Planetary Samples for Return to Earth

A system is proposed for packaging material samples on a remote planet (especially Mars) in sealed sample tubes in preparation for later return to Earth. The sample tubes (Figure 1) would comprise (1) tubes initially having open tops and closed bottoms; (2) small, bellows-like collapsible bodies inside the tubes at their bottoms; and (3) plugs to be eventually used to close the tops of the tubes. The top inner surface of each tube would be coated with solder. The side of each plug, which would fit snugly into a tube, would feature a solder-filled ring groove. The system would include equipment for storing, manipulating, filling, and sealing the tubes. The containerization system (see Figure 2) will be organized in stations and will include: the storage station, the loading station, and the heating station. These stations can be structured in circular or linear pattern to minimize the manipulator complexity, allowing for compact design and mass efficiency. The manipulation of the sample tube between stations is done by a simple manipulator arm. The storage station contains the unloaded sample tubes and the plugs before sealing as well as the sealed sample tubes with samples after loading and sealing. The chambers at the storage station also allow for plug insertion into the sample tube. At the loading station the sample is poured or inserted into the sample tube and then the tube is topped off. At the heating station the plug is heated so the solder ring melts and seals the plug to the sample tube. The process is performed as follows: Each tube is filled or slightly overfilled with sample material and the excess sample material is wiped off the top. Then, the plug is inserted into the top section of the tube packing the sample material against the collapsible bellowslike body allowing the accommodation of the sample volume. The plug and the top of the tube are heated momentarily to melt the solder in order to seal the tube

Acoustic Processing of Fluidic Samples for Planetary Exploration

The search for life on other planetary bodies is driven by our quest to determine if Earth is unique with respect to harboring life. In order to answer this question, instrumentation with suitable sensitivity is required to measure biosignatures. In addition to accurate measurements by in-situ instruments, specialized sample acquisition and sample handling hardware is required to maximize the scientific information obtained from an acquired sample. This paper discusses a class of compact sample processing instrumentation using solid-state mechanisms that use acoustic waves to process samples prior to delivery to the instrument. Some of the acoustic sample processes that can be used to aid in preparation of liquid and liquid/solid mixtures include: mixing, milling, cavitating, lysing, heating, streaming, stirring, lofting, concentrating, segregating, and filtering. We will review these acoustic processes and show how they are generated using electromechanical systems. In addition to processing, these transduction systems could also use acoustics to interrogate physical properties such as the state of the sample, the acoustic velocity, and its attenuation. In order to generate these processes and sensing capabilities at these frequencies, a transduction mechanism is required to produce stress waves from electrical signals and vice versa. One commonly used technique is to use piezoelectric transducers that generate a stress that is linearly proportional to the voltage across the transducer and a voltage that is proportional to the stress on a transducer’s face. A variety of transducer modes are available to excite the sample, including thickness, transverse, radial, and shear extensional, and these can be used to build composite resonance structures including ultrasonic horns, tuning forks, bimorph, and unimorph benders to increase stress generated in the sample. We discuss how to model the acoustic interactions with the sample and the sample chamber in order to produce the required stress waves and illustrate the use of network models of piezoelectric transducers to accomplish this modeling. We demonstrate how to build up these models using Mason’s equivalent circuit for a piezoelectric and network models for acoustic layers in a design. Finally, to illustrate this acoustic processing ability, we will discuss a few systems that we have developed for sample handling systems for other planetary bodies like Mars and ocean worlds Enceladus and Europa

High temperature measurement and characterisation of piezoelectric properties

Currently available high performance piezoelectric materials, predominantly based on lead zirconate titanate (PZT), are typically limited to operating temperatures of around 200 °C or below. There are many applications in sectors such as automotive, aerospace, power generation and process control, oil and gas, where reliable operation at higher temperatures is required for sensors, actuators and transducers. New materials are being actively developed to meet this need. Development and application of new and existing materials requires reliable measurement of their properties under these challenging conditions. This paper reviews the current state of the art in measurement of piezoelectric properties at high temperature, including direct and converse piezoelectric measurements and resonance techniques applied to high temperature measurements. New results are also presented on measurement of piezoelectric and thermal expansion and the effects of sample distortion on piezoelectric measurements. An investigation of the applicability of resonance measurements at high temperature is presented, and comparisons are drawn between the results of the different measurement techniques. New results on piezoelectric resonance measurements on novel high temperature piezoelectric materials, and conventional PZT materials, at temperatures up to 600 °C are presented