Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Magnetic Sensor”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63
All sourcesNASA NTRSDOE OSTI
NASA NTRS2000

Progress in the Development of Mo-Au Transition-Edge Sensors for X-Ray Spectroscopy

X-ray microcalorimeters using transition-edge sensors (TES) show great promise for use in astronomical x-ray spectroscopy. We have obtained very high energy resolution (2.8 electronvolts at 1.5 kiloelectronvolts and 3.7 electronvolts at 3.3 kiloelectronvolts) in a large, isolated TES pixel using a Mo/Au proximity-effect bilayer on a silicon nitride membrane. We will discuss the performance and our characterization of that device. In order to be truly suitable for use behind an x-ray telescope, however, such devices need to be arrayed with a pixel size and focal-plane coverage commensurate with the telescope focal length and spatial resolution. Since this requires fitting the TES and its thermal link, a critical component of each calorimeter pixel, into a far more compact geometry than has previously been investigated, we must study the fundamental scaling laws in pixel optimization. We have designed a photolithography mask that will allow us to probe the range in thermal conductance that can be obtained by perforating the nitride membrane in a narrow perimeter around the sensor. This mask will also show the effects of reducing the TES area. Though we have not yet tested devices of the compact designs, we will present our progress in several of the key processing steps and discuss the parameter space of our intended investigations.

of Magnetic Calorimeters for Applications in X-ray↗
DOE OSTI2021

Electro-optical measurement of intense electric field on a high energy pulsed power accelerator

We describe a direct electro-optical approach to measuring a strong 118 MV/m narrow pulse width (~ 33 ns) electric field in the magnetically insulated transmission line (MITL) of a pulsed power accelerator. To date, this is the highest direct external electric field measured electro-optically in a pulsed power accelerator, and it is between two to three orders of magnitude higher than values reported in comparable high energy scientific experiments. The MITL electric field is one of the most important operating parameters in an accelerator and is critical to understanding the properties of the radiation output. However, accurately measuring these high fields using conventional pulsed power diagnostics is difficult due to the strength of interfering particles and fields. Our approach uses a free-space laser beam with a dielectric crystal sensor that is highly immune to electromagnetic interference and does not require an external calibration. Here we focus on device theory, operating parameters, laboratory and pulsed power accelerator experiments as well as challenges that were overcome in the measurement environment.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2020

Auxetic two-dimensional transition metal selenides and halides

Abstract Auxetic two-dimensional (2D) materials provide a promising platform for biomedicine, sensors, and many other applications at the nanoscale. In this work, utilizing a hypothesis-based data-driven approache, we identify multiple materials with remarkable in-plane auxetic behavior in a family of buckled monolayer 2D materials. These materials are transition metal selenides and transition metal halides with the stoichiometry MX (M = V, Cr, Mn, Fe, Co, Cu, Zn, Ag, and X = Se, Cl, Br, I). First-principles calculations reveal that the desirable auxetic behavior of these 2D compounds originates from the interplay between the buckled 2D structure and the weak metal–metal interaction determined by their electronic structures. We observe that the Poisson’s ratio is sensitive to magnetic order and the amount of uniaxial stress applied. A transition from positive Poisson’s ratio (PPR) to negative Poisson’s ratio (NPR) for a subgroup of MX compounds under large uniaxial stress is predicted. The work provides a guideline for the future design of 2D auxetic materials at the nanoscale.

2d materials↗
NASA NTRS2010

Longitudinal Proximity Effect, Lateral Inverse Proximity Effect, and Nonequilibrium Superconductivity in Transition-edge Sensors

We have recently shown that normal-metal/superconductor (N/S) bilayer TESs (superconducting Transition-Edge Sensors) exhibit weak-link behavior. Our measurements were explained in terms of a longitudinal proximity effect model in which superconducting order from the higher transition temperature leads is induced into the TES bilayer plane over remarkably long distances (up to 290 micron). Here we extend our understanding to include TESs with added noise-mitigating normal-metal structures (N structures). We explain our results of an effect converse to the longitudinal proximity effect (LoPE), the lateral inverse proximity effect (LaiPE), for which the order parameter in the N/S bilayer is reduced due to the neighboring N structures. We present resistance and critical current measurements as a function of temperature and magnetic field taken on square Mo/Au bilayer TESs with lengths ranging from 8 to 130 micron with and without added N structures. We observe the inverse proximity effect on the bilayer over in-plane distances many tens of microns and find the transition shifts to lower temperature scale approximately as the inverse square of the in-plane N-structure separation distance, without appreciable broadening of the transition width. We find TESs with added Au structures exhibit weak-link behavior as evidenced by exponential temperature dependence of the critical current and Josephson-like oscillations of the critical current with applied magnetic field. We also present evidence for nonequilbrium superconductivity and estimate a quasiparticle lifetime of 1.8 x 10(exp -10) s for the bilayer. The LoPE model is also used to explain the increased conductivity at temperatures above the bilayer's steep resistive transition

Sadleir, John E.↗
NASA NTRS2000

TOA Lightning Location Retrieval on Spherical and Oblate Spheroidal Earth Geometries

A simple linear algebraic solution is introduced for retrieving the location and time-of-occurrence of lightning ground strikes on a spherical Earth from a network of four or more time-of-arrival (TOA) sensors. Since the solution accounts for Earth curvature, it represents an extension to earlier planar model results described by Koshak et al. A test of the retrieval method is provided using computer-simulated data sets. The method is easy to comprehend and completely avoids reference to the mathematics of spherical hyperbolas such as discussed by Lewis. A quasi-analytic extension to the spherical Earth solution is provided for an oblate spheroidal Earth geometry, and the importance/relevance of oblate effects are discussed. Future application of these methods in support of the North American National Lightning Detection Network (NALDN) described by Cummins et al. is desirable, but additional theoretical investigations are required to incorporate magnetic bearing information into the present solution process.

Koshak, W. J.↗
NASA NTRSDate not supplied

Refinement of the Transition-edge Sensor Design for ATHENA X-IFU

The X-ray Integral Field Unit (X-IFU) instrument on the Advanced Telescope for High ENergy Astrophysics (ATHENA) is baselined to have 2376 transition-edge sensor (TES) microcalorimeter pixels in a single array. The required performance for X-IFU has been demonstrated on a kilo-pixel array of square TES’s with 50 m side length, and this is considered the baseline pixel design. However, over the last few years we have explored small modifications to this design in search of a globally optimized instrument performance. We have previously reported on investigations of extending the length of the TES’s and variations in the number of X-ray absorber support stems. Here we report on investigations of TES designs with a length of 50 m but narrower width. We will discuss the consequence of this on magnetic field sensitivity, resistive transition parameters, spectral performance, and ease of multiplexing. We will also discuss how the number and position of the absorber attachments influences the vibrational modes of the pixels, and the impact this may have on performance. Finally, we will present measurements of more substantial change options of our TES design, including more extreme TES geometries, the use of metal islands or etched holes in the silicon nitride membranes, and the position of wiring to minimize current-induced magnetic field effects. The exploration of all these changes to the design are not only useful for optimizing performance on X-IFU, but also guide our fundamental understanding of the key physics of TES microcalorimeters.

Nick Wakeham↗
NASA NTRS2001

An overview of results from the ion diagnostics sensors flown on DS1

The Deep Space 1 (DS1) mission has successfully validated the use of ion propulsion technology for interplanetary spacecraft. The NASA Solar Electric Propulsion (SEP) Technology Applications Readiness (NSTAR) Project developed the Ion Propulsion Subsystem (IPS) for DS1. As part of the NSTAR validation effort, the NSTAR Project included a diagnostics element to characterize the local environment produced during IPS operations and its effects on spacecraft subsystems and science instruments. An integrated, comprehensive set of diagnostics, the NSTAR Diagnostics Package (NPD) was developed and operated on DS1 to characterize the IPS environment. The DS1 Spacecraft Team officially assigned the name “IPS Diagnostics Subsystems (IDS)” to the NDP for the DS1 mission. During the technology validation phase of the DS1 mission, a large amount of data was collected from the IDS under a variety of IPS operating conditions. IDS was able to characterize the contamination environment, charge-exchange xenon ion and electron population and energies, plasma noise and electromagnetic noise, and magnetic fields associated with IPS. The results presented here describe the charge-exchange plasma, contamination, plasma wave/EMI, and DC magnetic environments critical to designers of future space missions using ion propulsion

Henty, M. D.↗
NASA NTRS2008

Delivery of Colloid Micro-Newton Thrusters for the Space Technology 7 Mission

Two flight-qualified clusters of four Colloid Micro-Newton Thruster (CMNT) systems have been delivered to the Jet Propulsion Laboratory (JPL). The clusters will provide precise spacecraft control for the drag-free technology demonstration mission, Space Technology 7 (ST7). The ST7 mission is sponsored by the NASA New Millennium Program and will demonstrate precision formation flying technologies for future missions such as the Laser Interferometer Space Antenna (LISA) mission. The ST7 disturbance reduction system (DRS) will be on the ESA LISA Pathfinder spacecraft using the European gravitational reference sensor (GRS) as part of the ESA LISA Technology Package (LTP). Developed by Busek Co. Inc., with support from JPL in design and testing, the CMNT has been developed over the last six years into a flight-ready and flight-qualified microthruster system, the first of its kind. Recent flight-unit qualification tests have included vibration and thermal vacuum environmental testing, as well as performance verification and acceptance tests. All tests have been completed successfully prior to delivery to JPL. Delivery of the first flight unit occurred in February of 2008 with the second unit following in May of 2008. Since arrival at JPL, the units have successfully passed through mass distribution, magnetic, and EMI/EMC measurements and tests as part of the integration and test (I&T) activities including the integrated avionics unit (IAU). Flight software sequences have been tested and validated with the full flight DRS instrument successfully to the extent possible in ground testing, including full functional and 72 hour autonomous operations tests. Delivery of the cluster assemblies along with the IAU to ESA for integration into the LISA Pathfinder spacecraft is planned for the summer of 2008 with a planned launch and flight demonstration in late 2010.

Precision Formation Flying↗
NASA NTRS2010

Longitudinal Proximity Effect, Lateral Inverse Proximity Effect, and Nonequilibrium Superconductivity in Transition-Edge Sensors

We have recently shown that normal-metal/superconductor (N /S) bilayer TESs (superconducting Transition-Edge Sensors) exhibit weak-link behavior. Our measurements were explained in terms of a longitudinal proximity effect model in which superconducting order from the higher transition temperature leads is induced into the TES bilayer plane over remarkably long distances (up to 290 micron). Here we extend our understanding to include TESs with added noise-mitigating normal-metal structures (N structures). We explain our results in terms of an effect converse to the longitudinal proximity effect (LoPE), the lateral inverse proximity effect (LaiPE), for which the order parameter in the N /S bilayer is reduced due to the neighboring N structures. We present resistance and critical current measurements as a function of temperature and magnetic field taken on square Mo/Au bilayer TESs with lengths ranging from 8 to 130 micron with and without added N structures. We observe the inverse proximity effect on the bilayer over in-plane distances many tens of microns and find the transition shifts to lower temperatures scale approximately as the inverse square of the in-plane N-structure separation distance, without appreciable broadening of the transition width. We find TESs with added Au structures exhibit weak-link behavior as evidenced by exponential temperature dependence of the critical current and Josephson-like oscillations of the critical current with applied magnetic field. We also present evidence for nonequilbrium superconductivity and estimate a quasiparticle lifetime of 1.8 x 10(exp -10) s for the bilayer. The LoPE model is also used to explain the increased conductivity at temperatures above the bilayer's steep resistive transition.

Sadleir, John E.↗
NASA NTRS2018

Imaging X-Ray Polarimetry Explorer Mission Attitude Determination and Control Concept

The goal of the Imaging X-Ray Polarimetry Explorer (IXPE) Mission is to expand understanding of high-energy astrophysical processes and sources, in support of NASA's first science objective in Astrophysics: "Discover how the universe works." X-ray polarimetry is the focus of the IXPE science mission. Polarimetry uniquely probes physical anisotropies-ordered magnetic fields, aspheric matter distributions, or general relativistic coupling to black-hole spin-that are not otherwise measurable. The IXPE Observatory consists of Spacecraft and Payload modules. The Payload includes three polarization sensitive, X-ray detector units (DU), each paired with its corresponding grazing incidence mirror module assemblies (MMA). A deployable boom provides the correct separation (focal length) between the DUs and MMAs. These Payload elements are supported by the IXPE Spacecraft. A star tracker is mounted directly with the deployed Payload to minimize alignment errors between the star tracker line of sight (LoS) and Payload LoS. Stringent pointing requirements coupled with a flexible structure and a non-collocated attitude sensor-actuator configuration requires a thorough analysis of control-structure interactions. A non-minimum phase notch filter supports robust control loop stability margins. This paper summarizes the IXPE mission science objectives and Observatory concepts, and then it describes IXPE attitude determination and control implementation. IXPE LoS pointing accuracy, control loop stability, and angular momentum management are discussed.

Attitude Determination and Contro↗
NASA NTRS2020

FOSSIL—Finding Our Cosmic Roots

FOSSIL (Fragments from the Origins of the Solar System and our Interstellar Locale) is a concept to explore the largest solar system object visible to the unaided eye—the zodiacal cloud. The cloud’s many dust particles are each a tiny time capsule from a comet or asteroid. The FOSSIL concept is for the in situ compositional analysis of interplanetary dust particles, and also of the particles passing through the solar system from interstellar space. By measuring the zodiacal and interstellar particles’ velocity vectors and compositions, the approach resolves fundamental questions about the solar system’s origins. The FOSSIL concept is to: (1) Discover whether today’s local interstellar dust matches the composition of the feedstock from which the solar system formed; (2) Determine whether comets’ fine-grained component preserves unprocessed pre-solar dust or shows signs of processing in the early solar system; and (3) Learn whether comets’ and asteroids’ organic material share a common source or formed from distinct reservoirs. The FOSSIL concept is based on the use of a Dust Telescope (DT) with the capability to measure the composition and the velocity vector of dust particles to unambiguously separate interstellar from interplanetary particles, and identify a subset of zodiacal particles that are exclusively cometary. In the DT, particles pass through the trajectory sensor unharmed and impact a target plate, where they are vaporized and partially ionized. The ions are electrostatically focused onto a detector where the time-of-flight mass spectrum is recorded, enabling measurement of the composition of the interstellar solids, detection of cometary minerals altered by high temperatures or exposure to liquid water in the early solar system, and the characterization of the organic materials from the comets and asteroids that are still being delivered to the Earth today. FOSSIL’s objectives crosscut several disciplines with planetary science. Astrophysics interests lie in understanding interstellar solar matter and the only debris disk accessible in situ. Heliophysics interest is in the verification of large-scale heliospheric magnetic field models by the measured effect on the motion of electrically charged interstellar dust. Reporting the makeup of interplanetary dust that ablates in our atmosphere is valuable to Earth sciences. FOSSIL’s DT is scalable and can be accommodated to a variety of mission opportunities, without restriction on launch dates, and for a large number of possible orbits.

Turner, Neal↗
DOE OSTI2022

High-Precision Mapping of Diamond Crystal Strain Using Quantum Interferometry

Crystal-strain variation imposes significant limitations on many quantum sensing and information applications for solid-state defect qubits in diamond. Thus, the precision measurement and control of diamond crystal strain is a key challenge. Here, we report diamond strain measurements with a unique set of capabilities, including micron-scale spatial resolution, a millimeter-scale field of view, and a 2-order-of-magnitude improvement in volume-normalized sensitivity over previous work, reaching 5(2)×10 -8 /√Hzμm -3 (with spin-strain coupling coefficients representing the dominant systematic uncertainty). We use strain-sensitive spin-state interferometry on ensembles of nitrogen-vacancy (N-V) color centers in single-crystal bulk diamond with low strain gradients. This quantum interferometry technique provides insensitivity to magnetic-field inhomogeneity from the electronic and nuclear spin bath, thereby enabling long N-V–ensemble electronic spin dephasing times and enhanced strain sensitivity, as well as broadening the potential applications of the technique beyond isotopically enriched or high-purity diamond. We demonstrate the strain-sensitive measurement protocol first on a confocal scanning laser microscope, providing quantitative measurement of sensitivity as well as three-dimensional strain mapping; and second on a wide-field-imaging quantum diamond microscope. Our strain-microscopy technique enables fast, sensitive characterization for diamond material engineering and nanofabrication; as well as diamond-based sensing of strains applied externally, as in diamond anvil cells or embedded diamond stress sensors, or internally, as by crystal damage due to particle-induced nuclear recoils.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS2008

NASA Tech Briefs, July 2008

Topics covered include: Torque Sensor Based on Tunnel-Diode Oscillator; Shaft-Angle Sensor Based on Tunnel-Diode Oscillator; Ground Facility for Vicarious Calibration of Skyborne Sensors; Optical Pressure-Temperature Sensor for a Combustion Chamber; Impact-Locator Sensor Panels; Low-Loss Waveguides for Terahertz Frequencies; MEMS/ECD Method for Making Bi(2-x)Sb(x)Te3 Thermoelectric Devices; Low-Temperature Supercapacitors; Making a Back-Illuminated Imager with Back-Side Contact and Alignment Markers; Compact, Single-Stage MMIC InP HEMT Amplifier; Nb(x)Ti(1-x)N Superconducting-Nanowire Single-Photon Detectors; Improved Sand-Compaction Method for Lost-Foam Metal Casting; Improved Probe for Evaluating Compaction of Mold Sand; Polymer-Based Composite Catholytes for Li Thin-Film Cells; Using ALD To Bond CNTs to Substrates and Matrices; Alternating-Composition Layered Ceramic Barrier Coatings; Variable-Structure Control of a Model Glider Airplane; Axial Halbach Magnetic Bearings; Compact, Non-Pneumatic Rock-Powder Samplers; Biochips Containing Arrays of Carbon-Nanotube Electrodes; Nb(x)Ti(1-x)N Superconducting-Nanowire Single-Photon Detectors; Neon as a Buffer Gas for a Mercury-Ion Clock; Miniature Incandescent Lamps as Fiber-Optic Light Sources; Bidirectional Pressure-Regulator System; and Prism Window for Optical Alignment. Single-Grid-Pair Fourier Telescope for Imaging in Hard-X Rays and gamma Rays Range-Gated Metrology with Compact Optical Head Lossless, Multi-Spectral Data Compressor for Improved Compression for Pushbroom-Typetruments.

Source record↗
NASA NTRS1981

Bit error rate performance of Image Processing Facility high density tape recorders

The Image Processing Facility at the NASA/Goddard Space Flight Center uses High Density Tape Recorders (HDTR's) to transfer high volume image data and ancillary information from one system to another. For ancillary information, it is required that very low bit error rates (BER's) accompany the transfers. The facility processes about 10 to the 11th bits of image data per day from many sensors, involving 15 independent processing systems requiring the use of HDTR's. When acquired, the 16 HDTR's offered state-of-the-art performance of 1 x 10 to the -6th BER as specified. The BER requirement was later upgraded in two steps: (1) incorporating data randomizing circuitry to yield a BER of 2 x 10 to the -7th and (2) further modifying to include a bit error correction capability to attain a BER of 2 x 10 to the -9th. The total improvement factor was 500 to 1. Attention is given here to the background, technical approach, and final results of these modifications. Also discussed are the format of the data recorded by the HDTR, the magnetic tape format, the magnetic tape dropout characteristics as experienced in the Image Processing Facility, the head life history, and the reliability of the HDTR's.

Heffner, P.↗
NASA NTRS1993

Diffusion coefficients of energetic water group ions near Comet Giacobini-Zinner

Data from the ultralow-energy charge analyzer and energetic particle anisotropy spectrometer sensors, acquired when the ICE spacecraft flew past Comet Giacobini-Zinner on September 11, 1985, are combined, and a single, self-consistent analysis technique is applied to derive a single-particle spectrum from about 200 to 1600 km/s. This information, together with the deduced bulk flow speed of the ions, is used to calculate a parallel diffusion coefficient in the transition region downstream of the bow wave (2.3 +/- 0.5) x 10 exp 17 sq cm/s; the corresponding scattering mean free path is (6 +/- 1) x 10 exp 4 km. The parallel diffusion coefficient is found to depend on the collision frequency of water group ions with Alfven waves, which are assumed to be propagating parallel (antiparallel) to the magnetic field.

Tan, L. C.↗
NASA NTRS1999

Soil Analysis Micro-Mission Concepts Derived from the MSP 2001 Mars Environmental Compatibility Assessment (MECA)

The Mars Environmental Compatibility Assessment (MECA) will evaluate the Martian environment for soil and dust-related hazards to human exploration as part of the Mars Surveyor Program 2001 Lander. The integrated MECA payload contains a wet-chemistry laboratory, a microscopy station, an electrometer to characterize the electrostatic environment, and arrays of material patches to study abrasion and adhesion. Heritage will be all-important for low cost micro-missions, and adaptations of instruments developed for the Pathfinder, '98 and '01 Landers should be strong contenders for '03 flights. This talk has three objectives: (1) Familiarize the audience with MECA instrument capabilities; (2) present concepts for stand-alone and/or mobile versions of MECA instruments; and (3) broaden the context of the MECA instruments from human exploration to a comprehensive scientific survey of Mars. Due to time limitations, emphasis will be on the chemistry and microscopy experiments. Ion-selective electrodes and related sensors in MECA's wet-chemistry laboratory will evaluate total dissolved solids, redox potential, pH, and the concentration of many soluble ions and gases in wet Martian soil. These electrodes can detect potentially dangerous heavy-metal ions, emitted pathogenic gases, and the soil's corrosive potential, and experiments will include cyclic voltammetry and anodic stripping. For experiments beyond 2001, enhancements could allow multiple use of the cells (for mobile experiments) and reagent addition (for quantitative mineralogical and exobiological analysis). MECA's microscopy station combines optical and atomic-force microscopy (AFM) in an actively focused, controlled illumination environment to image particles from millimeters to nanometers in size. Careful selection of substrates allows controlled experiments in adhesion, abrasion, hardness, aggregation, magnetic and other properties. Special tools allow primitive manipulation (brushing and scraping) of samples. Soil particle properties including size, shape, color, hardness, adhesive potential (electrostatic and magnetic), will be determined using an array of sample receptacles and collection substrates. The simple, rugged atomic-force microscope will image in the submicron size range and has the capability of performing a particle-by-particle analysis of the dust and soil. Future implementations might enhance the optical microscopy with spectroscopy, or incorporate advanced AFM techniques for thermogravimetric and chemical analysis.

Hecht, M. H.↗
NASA NTRS2004

Space Station Biological Research Project (SSBRP) Cell Culture Unit (CCU) and incubator for International Space Station (ISS) cell culture experiments

The CCU and Incubator are habitats under development by SSBRP for gravitational biology research on ISS. They will accommodate multiple specimen types and reside in either Habitat Holding Racks, or the Centrifuge Rotor, which provides selectable gravity levels of up to 2 g. The CCU can support multiple Cell Specimen Chambers, CSCs (18, 9 or 6 CSCs; 3, 10 or 30 mL in volume, respectively). CSCs are temperature controlled from 4-39 degrees C, with heat shock to 45 degrees C. CCU provides automated nutrient supply, magnetic stirring, pH/O2 monitoring, gas supply, specimen lighting, and video microscopy. Sixty sample containers holding up to 2 mL each, stored at 4-39 degrees C, are available for automated cell sampling, subculture, and injection of additives and fixatives. CSCs, sample containers, and fresh/spent media bags are crew-replaceable for long-term experiments. The Incubator provides a 4-45 degrees C controlled environment for life science experiments or storage of experimental reagents. Specimen containers and experiment unique equipment are experimenter-provided. The Specimen Chamber exchanges air with ISS cabin and has 18.8 liters of usable volume that can accommodate six trays and the following instrumentation: five relocatable thermometers, two 60 W power outlets, four analog ports, and one each relative humidity sensor, video port, ethernet port and digital input/output port.

NASA Center ARC↗
DOE OSTI2022

Colossal piezoresistance in narrow-gap Eu 5 In 2 Sb 6

Piezoresistance, the change of the electrical resistance (R) of a material in response to an applied mechanical stress (σ), is the driving principle of electromechanical devices such as strain gauges, accelerometers, and cantilever force sensors. Enhanced piezoresistance has been traditionally observed in two classes of uncorrelated materials: nonmagnetic semiconductors and composite structures. In this study, we report the discovery of a remarkably large piezoresistance in Eu 5 In 2 Sb 6 single crystals, wherein anisotropic metallic clusters naturally form within a semiconducting matrix due to electronic interactions. Eu 5 In 2 Sb 6 shows a highly anisotropic piezoresistance, and uniaxial pressure along [001] of only 0.4 GPa leads to a resistivity drop of >99.95%, which results in a colossal piezoresistance factor of 5000×10 –11 Pa –1 . Our result not only reveals the role of interactions and phase separation in the realization of colossal piezoresistance, but it also highlights a route to multifunctional devices with large responses to both pressure and magnetic field.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗