Breadboard System Research Articles

Development of a high-resolution, broadband spatial heterodyne Raman spectrometer based on field-widened grating-echelle structure

We propose a spatial heterodyne Raman spectrometer (SHRS) based on a field-widened grating-echelle (FWGE). A normal grating is combined with an echelle grating in a conventional spatial heterodyne spectrometer to eliminate ghost images without using masks, and prevents interference among the spatial frequencies of different diffraction orders. Mathematical expressions and derivation processes are given for the spectral parameters in the FWGE-SHRS and a verification breadboard system is fabricated. The FWGE-SHRS measures Raman spectra of single chemicals and mixed targets with different integration times, laser powers, concentrations, and transparent containers. The results of the experiments demonstrate that the FWGE-SHRS is suitable for high-resolution, broadband Raman measurements for a wide range of applications.

Broadband, high-resolution spatial heterodyne Raman spectroscopy measurement based on a multi-Littrow-angle multi-grating.

This paper proposes a spatial heterodyne Raman spectrometer (SHRS) based on a multi-Littrow-angle multi-grating (MLAMG). Compared with a conventional multi-grating, the MLAMG not only provides higher spectral resolution and a broader spectral range, but is also easier to produce. A verification breadboard system is built using the MLAMG combined with four sub-gratings with a groove density of 300 gr/mm and Littrow angles of 4.6355°, 4.8536°, 5.0820°, and 5.3253°. This MLAMG-SHRS is used to obtain the Raman spectra of inorganic solids and organic solutions for different integration times, laser powers, suspension contents, and containers. The Raman spectra of mixed targets and minerals are also presented. The experiments demonstrate that the MLAMG-SHRS is suitable for broadband measurements at high spectral resolution in a wide range of potential applications.

Progress of Solid Oxide Electrolysis and Fuel Cells for Hydrogen Generation, Power Generation, Grid Stabilization, and Power-to-X Applications

Over the past 25+ years, Nexceris has been developing solid oxide cell (SOC) technology for power generation, energy storage and hydrogen production applications. Nexceris is vertically integrated SOC technology provider that develops and manufactures solid oxide electrode materials, interconnect coatings, planar electrolyte supported cells, and solid oxide stacks. Nexceris stacks are designed for low-cost manufacture and pressurized operation, and stacks have large repeat unit area for efficient packaging into megawatt-scale systems. Nexceris’ stacks are being tested in fuel cell, electrolysis, and reversible modes, with a focus on optimizing performance, efficiency, and durability. Current work at Nexceris includes long-term electrolysis stack durability testing, breadboard system testing of reversible SOC stacks, third-party stack validation testing, and SOC system design and demonstration testing. Nexceris also is exploring solid oxide co-electrolysis for converting steam and CO2 to syngas and the conversion of this syngas to fuels and chemicals. This presentation will provide an update on Nexceris’ solid oxide cell technology development and commercialization activities.

Benchmarking and Simulation of Solid-Oxide Steam Electrolysis for Propellant Production in a Vacuum Chamber-Simulated Lunar Environment

NASA and other space agencies have prioritized the development of in-situ resource utilization (ISRU) technology for producing critical materials such as propellants in space. Electrolysis to split water found in lunar, asteroid, and Martian environments provides a pathway for liquid H2 and O2 production, but the challenges of deploying such technology in extraterrestrial environments put an extreme emphasis on minimizing specific energy (measured in kWhelec/kgH2) and system specific mass (system kg/(kgH2/h)). High-temperature, solid oxide electrolysis cell (SOEC) systems have the potential to achieve lower specific energy than conventional liquid-phase alkaline and polymer electrolyte membrane (PEM) electrolysis systems, but this requires efficient thermal integration and minimization of balance of plant loads in order to take advantage of the lower electrolysis voltages for steam (vs. liquid H2O). The high operating temperatures of SOECs, however, require significant system mass for steam generators, heat exchangers for recuperation, and insulation of the electrolysis stack, particularly for space applications where ambient temperatures may be extremely low.This NASA-sponsored collaboration between OxEon Energy and Colorado School of Mines explored the feasibility of a lunar-based SOEC system, which was modeled and demonstrated at the lab-scale by operating a breadboard system, consisting of a SOEC stack and associated balance of plant BOP) in a cryogenic vacuum chamber in order to simulate a lunar environment. The combined »2.5-kWelec SOEC stack and BOP achieved a specific energy < 50 kWhelec/kgH2 at an H2 production rate of > 0.075 kgH2/h operating in the cryo-vacuum chamber.This study has benchmarked system-level models of the lab-scale SOEC stack based on doped-zirconia electrolytes fabricated at OxEon and designed to operate near thermoneutral voltage (1.28 V/cell) at 800°C. The stack BOP includes a steam generator, an oil-free scroll compressor, cathode and anode exhaust recuperators, and a H2 dryer, which uses cold incoming liquid water feeds to cool the cathode exhaust and condense most of the excess H2O in the H2 product stream out. Operation of this demonstration system provides a basis for designing scaled-up lunar fuel production systems of 40 kgH2/h. The success of the lab-scale tests in terms of thermal integration and the benchmarked models suggest a pathway to such a full-scale SOEC system that can achieve < 46 kWhelec/kgH2 with much lower specific mass.Both the modeling and the lab-scale demonstration tests revealed that system specific energy was most sensitive to stack steam utilization, and that achieving < 50 kWhelec/kgH2 required stack steam utilization > 75%. In addition, effective thermal integration that limited the electrical heating primarily to steam generation is critical to minimizing the SOEC-system BOP loads. The stack was shown to run reliably at steam utilizations > 90% with a single pass feed. Efforts will be presented on how to simulate such high utilization at larger scales for full lunar deployment. Additional testing of the lab-scale system in larger cryo-vacuum chambers at NASA during 2023 will allow for further confirmation of thermal management strategies to ensure reliable SOEC operation for lunar production of H2/O2 propellants.

Update on Nexceris’ Solid Oxide Fuel Cell Stack Technology

Over the past several years Nexceris has advanced its solid oxide fuel cell (SOFC) stack technology through innovations in materials, design, and operation. Sustainable fuel cell operation of Nexceris’ lightweight stack at high current density (0.5 – 0.7 A/cm²) and fuel utilization (70 – 80%) yields both high gravimetric power density and electrical efficiency. Stack robustness against thermal gradients, thermal cycling, and one-off events has been achieved through a combination of design modifications, sealing advancements, and operational protocols. Meanwhile, Nexceris’ stack technology maintains the key advantages of its patented FlexCell planar cell design, internal reforming capability, and tolerance to sulfur impurities in military logistic fuels.Recent and ongoing work at Nexceris includes stack demonstrations in breadboard systems and at customer sites, scale-up of stack manufacturing capabilities, and the development of a 10-kW stack module, opening the door to large-scale distributed generation and energy storage applications. This presentation will provide an update on the status and capabilities of Nexceris’ SOFC stacks and cost-saving approaches to stack fabrication.

Wide‐view augmented reality display with diffractive cholesteric liquid crystal lens array

AbstractA novel augmented reality display is proposed to achieve a field of view of 100°, while maintaining a good form factor with a glass‐thin waveguide combiner. The out‐coupler consists of an array of off‐axis diffractive lenslets with extremely low f‐number. A breadboard system is built and its performance characterized, combined with analysis and discussion of further improvement.

Update on Nexceris' SOFC Stack Technology

Over the past several years, Nexceris has been developing solid oxide fuel cell (SOFC) stacks based on its patented FlexCell planar cell design. The FlexCell is an electrolyte-supported planar SOFC cell design based on a thin electrolyte membrane layer that is mechanically supported by a mesh of electrolyte material, this design enables high performance at targeted operating temperature range of 750 to 850°C. The dense cell periphery provides an optimum sealing surface, and thin anode layers in the FlexCell enable high single-pass fuel utilization without sacrificing performance. Nexceris has demonstrated that SOFC stacks built with this technology are capable of providing targeted power outputs with high single-pass fuel utilization (up to 80 percent), and achieving high efficiencies (45 to 50 percent, LHV basis) when operating on reformed hydrocarbon fuels. More recently Nexceris has leveraged these attributes to establish a stack design which also enables exceptionally high gravimetric power density. Another key capability of Nexceris’ stacks is unprecedented performance and stability with sulfur containing fuels, an enabling attribute for SOFC systems operating on military logistic fuels (such as JP-8). Nexceris’ stacks exhibit stable operation with reformate fuels having as much as 50 ppm H2S, with test durations of 500 hours. Ongoing work is aimed at designing high efficiency SOFC systems based on Nexceris’ high power density and sulfur tolerant stack attributes. This work is supported by utilizing an in-house built process model which can accurately predict stack and system performance over a wide array of operating conditions (starting fuel, reforming conditions, fuel flow rate and utilization, cell area, number of cells, etc.). Nexceris currently is demonstrating its SOFC technology at 1-5 kW scale via in-furnace stack testing, ex-furnace hot box testing, and breadboard system testing. This presentation will provide a status update on Nexceris’ SOFC technology.

Update on Nexceris' SOFC Stack Technology

Over the past several years, Nexceris has been designing high efficiency SOFC systems based on Nexceris’ high power density, sulfur tolerant, and internal reforming stack attributes. This work is supported by utilizing an in-house built process model which can accurately predict stack and system performance over a wide array of operating conditions (starting fuel, reforming conditions, fuel flow rate and utilization, cell area, number of cells, etc.). Nexceris currently is demonstrating its SOFC technology at 1-5 kW scale via in-furnace stack testing, ex-furnace hot box testing, and breadboard system testing. This paper will provide a status update on Nexceris’ SOFC technology and design capabilities.

Experimental evaluation of a small-capacity, waste-heat driven ammonia-water absorption chiller

This paper presents the results from an experimental evaluation of a small-scale, waste-heat driven ammonia-water absorption chiller. The cycle is thermally driven, using the waste heat from diesel generator exhaust to desorb the refrigerant solution. The absorber and condenser are directly-coupled to the ambient air. The remaining heat exchangers are packaged in a compact microchannel monolithic structure for enhancing heat transfer. The system is designed to deliver 2.71-kW of cooling at extreme ambient temperature of 51.7 °C at a coefficient of performance of 0.55. Experiments on a heat pump breadboard system are conducted at ambient conditions of 29.7–44.2 °C, with delivered cooling duties of 2.54–1.91 kW. System and individual component performance is analyzed and compared with cycle model predictions, and deviations are explained. The absorber and desorber were identified to be the limiting components in the system. Effects of variation in ambient temperature are studied to characterize the performance at off-design conditions.

Biomimetic Optical-Filter Detection System for Discrimination of Infrared Chemical Signatures.

Optical-filter-based chemical sensors have the potential to dramatically alter the field of hazardous materials sensing. Such devices could be constructed using inexpensive components, in a small and lightweight package, for sensing hazardous chemicals in defense, industrial, and environmental applications. Filter-based sensors can be designed to mimic human color vision. Recent developments in this field have used this approach to discriminate between strongly overlapping chemical signatures in the mid-infrared. Reported work relied on using numerically filtered FTIR spectra to model the infrared biomimetic detection methodology. While these findings are encouraging, further advancement of this technique requires the collection and evaluation of directly filtered data, using an optical system without extensive numerical spectral analysis. The present work describes the design and testing of an infrared optical breadboard system that uses the biomimetic mammalian color-detection approach to chemical sensing. The set of chemicals tested includes one target chemical, fuel oil, along with two strongly overlapping interferents, acetone and hexane. The collected experimental results are compared with numerically filtered FTIR spectral data. The results show good agreement between the numerically filtered data model and the data collected using the optical breadboard system. It is shown that the optical breadboard system is operating as expected based on modeling and can be used for sensing and discriminating between chemicals with strongly overlapping absorption bands in the mid-infrared.

What can in situ ion chromatography offer for Mars exploration?

The successes of the Mars exploration program have led to our unprecedented knowledge of the geological, mineralogical, and elemental composition of the martian surface. To date, however, only one mission, the Phoenix lander, has specifically set out to determine the soluble chemistry of the martian surface. The surprising results, including the detection of perchlorate, demonstrated both the importance of performing soluble ion measurements and the need for improved instrumentation to unambiguously identify all the species present. Ion chromatography (IC) is the state-of-the-art technique for soluble ion analysis on Earth and would therefore be the ideal instrument to send to Mars. A flight IC system must necessarily be small, lightweight, low-power, and have low eluent consumption. We demonstrate here a breadboard system that addresses these issues by using capillary IC at low flow rates with an optimized eluent generator and suppressor. A mix of 12 ions known or plausible for the martian soil, including 4 (oxy)chlorine species, has been separated at flow rates ranging from 1 to 10 μL/min, requiring as little as 200 psi at 1.0 μL/min. This allowed the use of pneumatic displacement pumping from a pressurized aluminum eluent reservoir and the elimination of the high-pressure pump entirely (the single heaviest and most energy-intensive component). All ions could be separated and detected effectively from 0.5 to 100 μM, even when millimolar concentrations of perchlorate were present in the same mixtures.

Fast, compact, autonomous holographic adaptive optics.

We present a closed-loop adaptive optics system based on a holographic sensing method. The system uses a multiplexed holographic recording of the response functions of each actuator in a deformable mirror. By comparing the output intensity measured in a pair of photodiodes, the absolute phase can be measured over each actuator location. From this a feedback correction signal is applied to the input beam without need for a computer. The sensing and correction is applied to each actuator in parallel, so the bandwidth is independent of the number of actuator. We demonstrate a breadboard system using a 32-actuator MEMS deformable mirror capable of operating at over 10 kHz without a computer in the loop.

The effect of cancer cells on angiogenesis: engineering the cancer niche (676.13)

Tumor growth requires uncontrolled angiogenesis, defined as the growth of new capillaries from existing blood vessels. Developing anti‐tumor therapies necessitates understanding how cancer cells and their microenvironment synergistically influence capillary sprouting from existing vascular networks. Recently, we demonstrated the use of the rat mesentery culture model for investigating angiogenesis in an intact microvascular network scenario. The objective of this study was to demonstrate the use of this model to determine the effects of cancer cells on angiogenesis. Mesenteric tissue windows were harvested from adult male Wistar rats and cultured for 5 days according to the following experimental groups: 1) Control (MEM + 10% DMEM + 1% FBS; n = 7 tissues) and 2) Cancer Cell (MEM + 10% DMEM + 1% FBS + cells; n = 6 tissues). For the cancer cell group, 2x10^5 RFP‐transfected metastatic MDA‐MB‐231 breast cancer cells were seeded onto tissues on day 0. On day 5, cancer cells remained viable, as confirmed by live/dead assay. More importantly, cells were observed to be in the same focal plane and region as vessels along intact microvascular networks. The presence of cancer cells decreased vascular length density and the number of capillary sprouts per vascular area compared to the Control (no cell) group. Our results suggest that cancer cells alone are not sufficient to induce angiogenesis. Application of the rat mesentery culture model as a multicellular breadboard system to engineer the cancer cell/vascular niche will offer a new tool for tumor angiogenesis research.Grant Funding Source: Supported by Tulane Center for Aging and NIH 5‐P20GM103629‐02

Predistortion System Implementation Based On Analog Neural Networks For Linearizing High Power Amplifiers Transfer Characteristics

Abstract In order to correct non-linearities due to High Power Amplifiers (HPA) operating near saturation in telecommunication transceivers, a new adaptive predistortion system based on analog Neural Networks (NNs) was developed. Based on size, consumption and bandwidth considerations, Multi-Layer Perceptron (MLP) type NNs were implemented in a 0.6 μm CMOS ASIC. The NNs parameters are digitally updated with a computer, depending on simulation conditions (temperature drifts, ageing variations). The interface between the analog part and the software updating system is integrated in an analog-digital PCB including a FPGA, 6 analog-to-digital converters and 62 digital-to-analog converters. This paper describes the realization of each part of the breadboard system and presents experimental validation results of the whole predistortion module.

Searching for biomolecules on Mars: Considerations for operation of a life marker chip instrument

The search for life on Mars requires instruments that detect organic matter and discriminate between potential sources. One such instrument is the life marker chip that recognizes small molecules which are characteristic of particular organic provenances. The use of an antibody-based detection system requires the delivery of small organic compounds in a suitable solvent. Dedicated extraction protocols have been developed partly through the use of a life marker chip breadboard system. Techniques which provide the strong diagnostic potential of the life marker chip necessitate appropriate sample types. Clay mineral-rich rocks are attractive targets owing to their (i) association with liquid water, (ii) propensity for organic matter and clay mineral co-deposition following transport from a wide hinterland, and (iii) relatively large surface area and therefore potential for trapping/adsorption of organic materials. The most appropriate target organic compounds are the hydrocarbon-dominated lipids that can be highly diagnostic and have relatively high preservation potentials. The sample sites on Mars and sample preparation steps that are needed for successful detection require careful consideration. In this paper we explore the scientific results that may be obtained through the operation of a life marker chip instrument on Mars.

Testing of Lagrange multiplier damped least-squares control algorithm for woofer-tweeter adaptive optics

A Lagrange multiplier-based damped least-squares control algorithm for woofer-tweeter (W-T) dual deformable-mirror (DM) adaptive optics (AO) is tested with a breadboard system. We show that the algorithm can complementarily command the two DMs to correct wavefront aberrations within a single optimization process: the woofer DM correcting the high-stroke, low-order aberrations, and the tweeter DM correcting the low-stroke, high-order aberrations. The optimal damping factor for a DM is found to be the median of the eigenvalue spectrum of the influence matrix of that DM. Wavefront control accuracy is maximized with the optimized control parameters. For the breadboard system, the residual wavefront error can be controlled to the precision of 0.03 μm in root mean square. The W-T dual-DM AO has applications in both ophthalmology and astronomy.

Two-stage air-source heat pump for residential heating and cooling applications in northern U.S. climates

Air-source heat pumps for residential heating are more widely used than geothermal heat pumps mainly due to their lower installation costs. Major disadvantages of air-source heat pumps are the decrease of heat output and coefficient of performance (COP), and increase in discharge temperature, towards low outdoor temperatures. In this paper an air-source two-stage heat pump using R410A as the refrigerant was simulated, designed, constructed, and tested at ambient temperatures as low as −30 °C and supply temperatures of up to 50 °C in air and water heating mode. In addition, the system is able to provide sufficient air conditioning in cooling mode (approximately 50–60% of the design heat transfer rate in heating mode). A short summary of an extended literature review is shown as well as a theoretical screening study of the three most promising cycles. Furthermore, the design and test results of a breadboard system and a comparison with commercially available heat pumps are presented. Second law efficiencies of up to 45% could be achieved, resulting in a coefficient of performance (COP) of 2.1 at −30 °C ambient temperature.

심우주 지구 반사율 측정용 아몬라 가시광 채널의 광학 시스템 제조 및 성능 평가

지구와 태양 사이의 중력 평형점에서 혜일로 궤도로 운용되며, 심우주 반사율(albedo)을 측정코자 하는 EARTHSHINE 미션의 과학적 목적에 최적화된 아몬라 가시광 채널의 성능 인증 모델용 광학 시스템 개발을 완료하였다. 아몬라 광학계 설계 요구사항에 부합하는 설계안과 공차분석 결과를 바탕으로 광학 시스템의 설계, 부품 제작, 결합, 정렬, 성능 검증까지의 전 공정을 순수 국내 개발하였으며 특히 측정된 부품들의 광파면 오차를 결합 및 성능 평가 공정에 역투입하는 신 공법에 의하여 성능 검증을 실시하였다. 최종 결합 및 정렬이 완료되어 측정한 아몬라 광학계의 광파면 오차는 중심 시야에서 RMS 0.091 wave(기준 파장: 632.8nin)이며, Ensquared Energy(EE) 성능은 61.7%(<TEX>$14{\mu}m$</TEX> 이내), 변조전달함수(MTF) 성능은 35.3%(기준 주파수: <TEX>$35.7mm^{-1}$</TEX>)이다. 위 결과들은 아몬라 가시광 채널의 요구사항을 모두 만족시킴으로써 개발된 아몬라 가시광 채널 광학계가 EARTHSHINE 미션의 과학목적을 완수할 수 있음을 증명하였다. The AmonRa instrument, the primary payload of the international EARTHSHINE mission, is designed for measurement of deep space albedo from L1 halo orbit. We report the optical design, tolerance analysis and the optical performance of the breadborad AmonRa imaging channel instrument optimized for the mission science requirements. In particular, an advanced wavefront feedback process control technique was used for the instrumentation process including part fabrication, system alignment and integration. The measured performances for the complete breadboard system are the RMS 0.091 wave(test wavelength: 632.8 nm) in wavefront error, the ensquared energy of 61.7%(<TEX>$in\;14\;{\mu}m$</TEX>) and the MTF of 35.3%(Nyquist frequency: <TEX>$35.7\;mm^{-1}$</TEX>) at the center field. These resulting optical system performances prove that the breadboard AmonRa instrument, as built, satisfies the science requirements of the EARTHSHINE mission.

Development of an All-Fiber Coherent Laser Radar for Precision Range and Velocity Measurements

AbstractAn all-fiber coherent laser radar system capable of high-resolution range and line of sight velocity measurements is under development with a goal to aid NASA's new Space Exploration initiative for manned and robotic missions to the Moon and Mars. Precision range and velocity data are key parameters to navigating planetary landing pods to the pre-selected site and achieving autonomous safe soft-landing. By employing a combination of optical heterodyne and linear frequency modulation techniques [1-3] and utilizing state-of-the-art fiber optic technologies, highly efficient, compact and reliable laser radar suitable for operation in a space environment is being developed.The all-fiber coherent laser radar has several important advantages over more conventional pulsed laser altimeters or range finders. One of the advantages of the coherent laser radar is its ability to directly measure the platform velocity by extracting the Doppler shift generated by the platform motion. The Doppler velocity measurement is about two orders of magnitude more accurate than the velocity estimates obtained by laser altimeters using the rate of change in range [4]. Another advantage is continuous-wave operation that allows the use of highly efficient and reliable commercial off-the-shelf fiber optic telecommunication components. This paper will describe the design and operation of this laser radar sensor and discuss its projected performance. A laboratory breadboard system has already been developed as a step toward a flight prototype. The experimental data representing the potentials of this laser radar system will be reported.

Breadboard system and techniques to optimize the optical system of an encoder

The resolution and precision of an optical encoder are determined by three factors: (1) the distance between the photodetector and the slit disk, (2) the ratio of the width of the active area of the photodetector to the width of the slit of the slit disk, and (3) the concentricity of the photodetector and the slit disk. A quantitative analysis of these factors generally requires a grasp of sophisticated analytical techniques, including an incoherent spectrum, the optical system of the light emitting diode (LED), and diffraction. We propose a breadboard system and techniques for obtaining the same output signal as that of the actual encoder using the image data of the light intensity as it permeates the slit disk of the encoder, without the aid of the advanced analytical techniques generally required. We then compare the analytical result obtained with this technique with the output signal from the actual encoder to confirm the validity of this breadboard system and technique.