Recent experiments with a flextensional piezoelectric actuator have led to the development of a sampler with a bit that is designed to produce and capture a full set of sample forms including volatiles, powdered cuttings, and core fragments.

The flextensional piezoelectric actuator is a part of a series of devices used to amplify the generated strain from piezoelectric actuators. Other examples include stacks, bimorphs, benders, and cantilevers. These devices combine geometric and resonance amplifications to produce large stroke at high power density. The operation of this sampler/drill was demonstrated using a 3×2×1-cm actuator weighing 12 g using power of about 10-W and a preload of about 10 N. A limestone block was drilled to a depth of about 1 cm in five minutes to produce powdered cuttings.

The Miniature Drill, the bit, and the covering of both the actuator and bit using bellows are shown. The tube with bellows also is shown.
It is generally hard to collect volatiles from random surface profiles found in rocks and sediment, powdered cuttings, and core fragments. Toward the end of collecting volatiles, the actuator and the bit are covered with bellows-shaped shrouds to prevent fines and other debris from reaching the analyzer. A tube with a miniature bellows (to provide flexibility) is connected to the bit and directs the flow of the volatiles to the analyzer. Another modality was conceived where the hose is connected to the bellows wall directly to allow the capture of volatiles generated both inside and outside the bit. A wide variety of commercial bellows used in the vacuum and microwave industries can be used to design the volatiles’ capture mechanism.

The piezoelectric drilling mechanism can potentially be operated in a broad temperature range from about –200 to <450 °C. The actuators used here are similar to the actuators that are currently baselined to fly as part of the inlet funnel shaking mechanism design of MSL (Mars Science Laboratory). The space qualification of these parts gives this drill a higher potential for inclusion in a future mission, especially when considering its characteristics of low mass, small size, low power, and low axial loads for sampling.

Such a tiny penetrator can be integrated with instruments for life and water detection as well as materials characterization for planetary applications. It is also a useful tool for gaining subsurface access, an exploration goal that is an essential element of future missions. Terrestrially speaking, this tool has applications with regard to testing soil for toxic chemicals, the presence of moisture, and various other analytical tests.

This work was done by Stewart Sherrit, Mircea Badescu, and Yoseph Bar-Cohen of Caltech for NASA’s Jet Propulsion Laboratory. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp under the Mechanics/Machinery category.

In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:

Innovative Technology Assets Management
JPL
Mail Stop 202-233
4800 Oak Grove Drive
Pasadena, CA 91109-8099
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Refer to NPO-45857, volume and number

of this NASA Tech Briefs issue, and the page number.

Topics:
Chemicals Cutting Drilling Engine components Engine cooling systems Engines Hoses Machining processes Manufacturing processes Mechanical Components Mechanics Parts Powertrains Sensors and actuators Soils Vacuum Water
This Brief includes a Technical Support Package (TSP).
Document cover
Miniature Low-Mass Drill Actuated by Flextensional Piezo Stack

(reference NPO-45857) is currently available for download from the TSP library.

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NASA Tech Briefs Magazine

This article first appeared in the August, 2010 issue of NASA Tech Briefs Magazine (Vol. 34 No. 8).

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Overview

The document outlines the development of a Miniature Low-Mass Drill, actuated by a flextensional piezo stack, created by NASA's Jet Propulsion Laboratory (JPL). This innovative drill is designed for in-situ exploration of the solar system, capable of acquiring powdered cuttings, core fragments, and volatiles from various geological surfaces. Its compact size and lightweight design make it suitable for integration into lightweight manipulators and instruments for future space missions.

The primary problem addressed by the inventors was the need for an effective sampling mechanism that could operate in extreme environments, such as those found on celestial bodies like Europa, Titan, and Venus. The drill utilizes a flextensional piezoelectric actuator, which amplifies the stroke of the piezoelectric stack, allowing for strong vibrations in the kHz frequency range. This mechanism enables rapid hammering action, effectively breaking rock surfaces to collect samples.

Key features of the drill include its low mass, low power consumption, and low axial load, making it highly attractive for future NASA missions. The drill is capable of producing a variety of sample forms, including volatiles, powdered cuttings, and solid fragments, which are essential for geological analysis. The design incorporates a bit that captures these samples while minimizing the loss of volatiles, which are typically challenging to collect.

The document also highlights the successful initial lab experiments, where the drill demonstrated its capability by drilling into a limestone block and producing powdered cuttings. The drill's design includes protective shrouds to prevent debris from contaminating the samples and a flexible tube that directs volatiles to an analyzer.

Overall, the Miniature Low-Mass Drill represents a significant advancement in sampling technology, enabling new in-situ analysis applications for future space missions. Its novel features and capabilities position it as a vital tool for exploring and understanding the geological characteristics of other planets and moons, potentially leading to discoveries about their composition and the presence of volatiles. The document serves as a technical support package, providing insights into the drill's design, functionality, and potential applications in space exploration.