Miniaturization Of Instruments Research Articles

Triple‐Dome Electrostatic Energy Analyzer With 360° Field‐Of‐View for Simultaneous Measurements of Ions and Electrons

AbstractThe demonstrative space plasma physics communities in the world have been conducting intensive research and development activities for instrument miniaturization because compact and lightweight sensors are required for installation on micro/small satellites and CubeSats in ongoing and future space exploration missions. Recently, we designed a novel type of space plasma instrument capable of simultaneous energy analyses of low‐energy (∼eV to several 10s of keV) electrons and ions with a single sensor head consisting of triple‐dome analyzer with triple‐layer collimator for covering 360° field‐of‐view similar to that of the prevailing top‐hat type. Two separate but correlated electrostatic fields, produced by a single high‐voltage supply unit in double gaps of the triple‐dome/layer structures, are used for electron/ion energy analyses. In the breadboard model (BBM) designed here, the energy/angular resolutions and the analyzer constants (ratios of measured particle energy to applied voltage) are approximately 9.0%/3.5° and 4.0, and 10%/4° and 4.4 for the electron and ion energy analyses, respectively. We also fabricated the first BBM of the triple‐dome type of electrostatic analyzer for experimental performance tests in electron/ion beamline facility. According to the experimental data by the two‐dimensionally position‐sensitive particle detector, the calibrated properties of energy/angular analyses and the other sensor performance show good agreement with numerical design results. The performance of the triple‐dome analyzer would satisfy observation requirements, as represented by measurements of three‐dimensional velocity distributions of electrons and ions in future missions using spin‐type microsatellites/CubeSats under stringent resource conditions.

Design and Modeling of a Miniature Hydraulic Motor for Powering a Cutting Tool for Minimally Invasive Procedures.

Miniaturization of multifunctional instruments is key to evolving less invasive medical procedures. The current work outlines steps towards developing a miniature motor to power a cutting tool of a millimeter-scale robot/device (target outside diameter ~2 mm) for minimally invasive procedures. Multiple motor concepts were explored and ranked using a Pugh matrix. The single-rotor hydraulic design was deemed most viable for prototyping and scale-down to the target size. Prototypes were manufactured to be progressively smaller using additive manufacturing. The smallest prototype fabricated was 2:1 scale of the desired final size with a 2 mm outside diameter (OD) rotor and a device OD of 4 mm. The scaled prototypes with an 8 mm rotor were lab tested and achieved average speeds of 5000-6000 RPM at a flowrate of 15-18 mL/s and 45 PSI water pressure. Ansys CFX was used as a design tool to explore the parameter space and 3D transient simulations were implemented using the immersed solid method. The predicted rotor RPM from the modeling matched the experimental values within 3% error. The model was then used to develop performance curves for the miniature hydraulic motor. In summary, the single-rotor hydraulic design shows promise for miniaturization to the target 2 mm size.

Stone Free Rate of Lower Pole Calyceal Stone Versus Other Calyces in Retrograde Intrarenal Surgery

Background: Miniaturization of endoscopic instruments has gained wide popularity in the treatment of renal calculi. Retrograde intra-renal surgery (RIRS) and laser in combination has already proven their superiority when compared to other modalities in the treatment of renal calculi. This study was conducted to assess the stone-free rate (SFR) of lower pole calyceal stone versus other pole calyces in RIRS. Methods: This retrospective study analyzed the stone free rate of lower pole calyx stone versus other pole calyces in retrograde intra renal surgery (RIRS) adults above 15 years of age from March 2021 to February 2022 at Chitwan Medical College and Teaching Hospital, Nepal. The stone-free rate was assessed descriptively on post operative complications, stone size, operative time, hospital stay, and need for the second procedure. Results: A total of 62 patients underwent retrograde intrarenal surgery. The mean age of the study population was 38.41 ± 10.54years in the lower caliceal group against 39.09 ±13.53 years with p value of 0.829.The mean hounsfield of lower caliceal stone was 1023.31±252.96 to that of other caliceal stones 1004.00±349.22 with p value of 0.806. The sizes of the stones were 11.07±2.10 mm in lower caliceal stones versus 10.67±2.51mm in other caliceal stones with p value of 0.507. The duration of operation time in 1st group was 63.82±23.57minutes to that of 65.93±28.96 in 2nd group with p value of 0.756. The hospital stay in lower caliceal stones were 6.13±1.43days to that of other caliceal stones 5.87±0.99 with significant p value of 0.412. There were no major complications in both arms. The stone free rate was 25 (86.2%) in lower caliceal stones as compared to 31(93.93%) in other caliceal stones with no significant p value of 0.405. Conclusions: Retrograde intrarenal surgery is a better procedure that continues to undergo significant advancements. It is a technically safe and effective procedure for the treatment option for treating the lower pole calyx calculus with optimal post-surgical morbidity and stone-free rate.

Rapid and On-Scene Chemical Identification of Intact Explosives with Portable Near-Infrared Spectroscopy and Multivariate Data Analysis.

There is an ongoing forensic and security need for rapid, on-scene, easy-to-use, non-invasive chemical identification of intact energetic materials at pre-explosion crime scenes. Recent technological advances in instrument miniaturization, wireless transfer and cloud storage of digital data, and multivariate data analysis have created new and very promising options for the use of near-infrared (NIR) spectroscopy in forensic science. This study shows that in addition to drugs of abuse, portable NIR spectroscopy with multivariate data analysis also offers excellent opportunities to identify intact energetic materials and mixtures. NIR is able to characterize a broad range of chemicals of interest in forensic explosive investigations, covering both organic and inorganic compounds. NIR characterization of actual forensic casework samples convincingly shows that this technique can handle the chemical diversity encountered in forensic explosive investigations. The detailed chemical information contained in the 1350-2550 nm NIR reflectance spectrum allows for correct compound identification within a given class of energetic materials, including nitro-aromatics, nitro-amines, nitrate esters, and peroxides. In addition, the detailed characterization of mixtures of energetic materials, such as plastic formulations containing PETN (pentaerythritol tetranitrate) and RDX (trinitro triazinane), is feasible. The results presented illustrate that the NIR spectra of energetic compounds and mixtures are sufficiently selective to prevent false-positive results for a broad range of food-related products, household chemicals, raw materials used for the production of home-made explosives, drugs of abuse, and products that are sometimes used to create hoax improvised explosive devices. However, for frequently encountered pyrotechnic mixtures, such as black powder, flash powder, and smokeless powder, and some basic inorganic raw materials, the application of NIR spectroscopy remains challenging. Another challenge is presented by casework samples of contaminated, aged, and degraded energetic materials or poor-quality HMEs (home-made explosives), for which the spectral signature deviates significantly from the reference spectra, potentially leading to false-negative outcomes.

A Compact Full-disk Solar Magnetograph Based on Miniaturization of the GONG Instrument* *Submitted January XX, 2023.

The design of compact instruments is crucial for the scientific exploration by smaller spacecraft such as CubeSats and deep space missions, as these missions require minimal instrument mass. In this proof-of-concept study, we demonstrate the miniaturization of the Global Oscillation Network Group (GONG) instrument. GONG instruments routinely produce full-disk maps of the Sun’s photosphere using the Ni i 676 nm absorption line, measuring Doppler shifts and magnetic fields. To miniaturize the GONG optical design, we propose replacing the bulky Lyot filter with a narrow-band interference filter. We validate this concept through numerical modeling and proof-of-concept observations. Finally, we propose a simple optical design for building a compact version of GONG.

V02-03 MINI-PCNL: TIPS AND TRICKS TO SHORTEN YOUR LEARNING CURVE

You have accessJournal of UrologyCME1 Apr 2023V02-03 MINI-PCNL: TIPS AND TRICKS TO SHORTEN YOUR LEARNING CURVE Robert Brunner, Amit Reddy, Richard Link, and Wesley Mayer Robert BrunnerRobert Brunner More articles by this author , Amit ReddyAmit Reddy More articles by this author , Richard LinkRichard Link More articles by this author , and Wesley MayerWesley Mayer More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003232.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Standard antegrade percutaneous nephrolithotomy (PCNL) has long been an effective treatment option for moderate to large renal stones. The miniaturization of endoscopic instrumentation has led to the emergence of mini-PCNL as an increasingly popular option. For established practitioners unfamiliar with mini-PCNL or trainees exposed to these procedures for the first time, formal educational resources to shorten the learning curve are lacking. In this video, we present our technique for prone mini-PCNL, including obtaining direct vision ureteroscopically-guided access, dilating the access tract, facilitating efflux of fragments, placing a ureteral stent, and performing an intercostal nerve block. METHODS: Footage from four prone mini-PCNL cases was collected for editing and review. All were performed at a single academic institution under the supervision of the same attending physician to standardize technique across cases. Apple Imovie was used to edit video clips and create a cohesive educational step-by-step instructional video for trainees and attending physicians performing this procedure. In particular, the video describes a novel and technically simple technique for attaining “through-and-though” antegrade percutaneous access via a retrograde ureteroscopic approach and highlights helpful tips and tricks for optimizing a successful and efficient procedure. RESULTS: All patients underwent successful mini-PCNL without complications. All were discharged the same day with a ureteral stent and strings, which was removed by the patient within one week after surgery. The educational video was disseminated throughout our residency program for review by residents prior to participating in their first mini or standard PCNL procedure. CONCLUSIONS: Mini-PCNL can be used effectively for cases of moderate sized stones in which ureteroscopy may prove tedious, while improving stone-free rates, shortening operative times, and preserving same day discharge. Our educational video provides an easy, step-by-step process for trainees and attending physicians to shorten their learning curve and maximize success for their next mini-PCNL stone procedure. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e168 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Robert Brunner More articles by this author Amit Reddy More articles by this author Richard Link More articles by this author Wesley Mayer More articles by this author Expand All Advertisement PDF downloadLoading ...

MP23-01 A RANDOMISED CONTROLLED STUDY COMPARING STANDARD TUBELESS PCNL & TUBELESS MINI-PCNL FOR RENAL STONES LESS THAN 2 CM

You have accessJournal of UrologyCME1 Apr 2023MP23-01 A RANDOMISED CONTROLLED STUDY COMPARING STANDARD TUBELESS PCNL & TUBELESS MINI-PCNL FOR RENAL STONES LESS THAN 2 CM Aditya Yelikar Aditya YelikarAditya Yelikar More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003248.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: PCNL has become a standard minimally invasive treatment for renal stones. Tubeless PCNL is associated with less morbidity. Miniaturisation of instruments leads decrease morbidity of procedure. We compared standard tubeless PCNL to Miniperc tubeless PCNL for morbidity and stone free rates in order to improve outcomes of PCNL with minimal morbidity. METHODS: Our study included 100 patients, 50 patients in group 1 (standard tubeless PCNL) & 50 patients in group 2 (tubeless mini PCNL) , with single renal stone less than 2 cm. Patients with CKD, solitary kidney, ectopic kidney and previous diversion were excluded. Tract was dilated upto 24 Fr in group 1 & upto 16 Fr in group 2. No percutaneous nephrostomy was kept. Post operative pain score was monitored at 12 and 24 hours. Additional analgesia was given if needed. Hemoglobin was measured pre operatively & on post op day 1. Stone clearance was checked with ultrasonography & XRay KUB (kidney-ureter-bladder). Total Operative time , pain score, analgesic requirement, haemoglobin drop, complications (bleeding, fever, urinary leak, urosepsis, hydro or pneumothorax) and stone free rate were compared. RESULTS: Miniperc operative time was longer than standard PCNL (45±10 vs 35±8 mins. p<0.001). Median pain score at 12 and 24 hours was more in group 1 than in group 2 (6±1 VS 4±1, p<0.0001 and 3±1 vs 2±1, p<0.001). Post operative hemoglobin drop was more in group 1 than in group 2 (0.95±0.2 VS 0.6±0.1, p<0.0001). Stone clearance in group 1 was 100% while in group 2 it was 95%. There was no significant difference in complications between the two groups. CONCLUSIONS: Both Standard tubeless PCNL & tubeless Mini PCNL are effective for renal stones less than 2 cm. Operative time is more in tubeless Mini PCNL whereas pain score, analgesics requirement and hemoglobin drop are more in standard tubeless PCNL comparatively. Stone clearance in both groups is comparable and more than 95%. Source of Funding: Nil © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e306 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Aditya Yelikar More articles by this author Expand All Advertisement PDF downloadLoading ...

Small satellite formations and constellations for observing sub-daily mass changes in the Earth system

SUMMARY Satellite gravity missions so far are medium size satellites consisting of one or a pair of satellites flying in near-polar or sun-synchronous orbital planes. Due to the limited observation geometry and the related space–time sampling, high-frequency non-tidal mass variation signals from atmosphere and ocean cannot be observed and cause temporal aliasing. For current single-pair satellite gravimetry missions as GRACE and GRACE Follow-On (GRACE-FO) temporal aliasing is the limiting factor and represents the major error source in the gravity field time-series. Adding a second inclined satellite pair to a GRACE-like polar pair (Bender constellation) currently is the most promising solution to increase the spatio-temporal resolution and to significantly reduce the temporal aliasing error. This shall be implemented with the MAGIC mission in future. With the ongoing developments in miniaturization of satellites and gravity-relevant instruments (accelerometers and intersatellite ranging), in future constellations of multiple small satellite pairs may solve this problem even beyond the capabilities of a Bender constellation. Therefore, in this study the capabilities of such constellations flying in specific formations are investigated in order to enable a retrieval of the temporal gravity field on short time scales. We assess the performance of up to 18 satellite pairs. The satellite configurations cover satellite pairs in polar and inclined orbits flying in pair-wise or pearl-string formation with varying mean anomalies and right ascensions of the ascending node (RAAN). As future potential miniaturized instruments optomechanical accelerometers with similar performance as those flying on GRACE-FO are a candidate, while for the intersatellite ranging instrument still some technological development is required. Therefore, in this study a microwave ranging system equivalent to the GRACE and GRACE-FO instruments performance is taken as baseline assuming that such instruments can be miniaturized in future as well. In numerical closed-loop simulations, up to nine different satellite configurations with up to 18 satellite pairs are evaluated based on the retrieval of the non-tidal temporal gravity field on a monthly basis. From the simulation results it is concluded that the best-performing satellite constellation of 18 polar satellite pairs already is outperformed by a typical Bender-like constellation of 1 polar and 1 inclined pair. In general, we identify that increasing the number of satellite pairs leads to an improved gravity field retrieval, either at low spherical harmonic degree and order (d/o) by the shift in RAAN or at high d/o by the shift in mean anomaly. By a two-step simulation approach, co-estimating also (sub-)daily gravity fields for selected configurations with a large number of satellite pairs distributed equally over the globe, it is possible to retrieve stand-alone gravity fields at 24, 12 and 6 hr temporal resolution. Ultimately it is concluded that a network of miniaturized satellites with instrument performances similar to GRACE-FO and flying in a well-defined constellation has the potential to observe (sub-)daily mass variations and therefore could drastically reduce the problem of temporal aliasing due to high frequency mass variations in the Earth system.

Technology Focus: Digital Data Acquisition (January 2023)

With the rise of machine learning and other artificial intelligence methods, the ability to digest data for potential application in the petroleum industry has increased tremendously. Data is seen as the key to reducing uncertainty in decisions for this capital‑intensive industry where the costs of bad or delayed decisions are huge. Thus, the right data delivered at the right time can revolutionize the industry and save precious time and money. Gaining insights from digital data in the highly technical exploration and production industry requires experience, knowledge, and awareness about the acquisition of the data. The technologies presented here aim to facilitate the decision‑making process while requiring less time and lower costs without sacrificing the accuracy of the data and still decreasing the probability of human errors. They show how data collected from different vantage points can be integrated with conventional data‑acquisition methods to help visualize and reduce the uncertainty of the subsurface. Developments in other industries in automation and electronics have enabled modernization and miniaturization of oilfield instruments. Our industry seeks ideas and methods that are reliable, convenient, and practical to inform and guide operations, filling the gaps where and when conventional data is not available. Recommended additional reading at OnePetro: www.onepetro.org. OTC 31327 Density Measurement of Three-Phase Flows Inside Vertical Piping Using Planar Laser-Induced Fluorescence by Amy Brooke McCleney, Southwest Research Institute, et al. OTC 31836 Subsea Multiphase Flowmeter Measurement Performance Assurance With an Applied Data Validation and Reconciliation Surveillance Methodology by Emmelyn Graham, BP, et al. SPE 208712 IADC Code Upgrade: Data Collection and Work Flow Required To Conduct Bit Forensics and Create Effective Changes in Practices or Design by William Watson, Shell, et al.

Enhancing UAV images to improve the observation of submerged whales using a water column correction method

Enhancing <scp>UAV</scp> images to improve the observation of submerged whales using a water column correction method

Vasovagal Syncope during Office Hysteroscopy-A Frequently Overlooked Unpleasant Complication.

Due to technological advancements in miniaturization of instruments and improved optics, the number of office hysteroscopic procedures has increased over time. Office hysteroscopy is preferred due to avoidance of general anesthesia and decreased overall cost. Vasovagal syncope has been implied as the most common complication. Vasovagal syncope is associated with inappropriate reflex vasodilation and bradycardia in the setting of an acute malfunction between the autonomic nervous system and the cardiovascular system; however, there is no mortality associated with vasovagal syncope. A management strategy for acute vasovagal reflex during office hysteroscopy is proposed in order to manage this common complication.

Electroactive Polymer-Based Spray Ionization for Direct Mass Spectrometric Analysis.

Electrochemically deposited electroactive polymer (EAP) films were investigated for their potential to enhance the performance of ambient ionization mass spectrometry (MS). Several EAPs of varying hydrophobicity were evaluated, including the superhydrophobic polymer poly[3,4-(2-dodecylethylenedioxy)thiophene] (PEDOT-C12). The EAPs were electropolymerized onto indium tin oxide-coated glass, placed in front of the inlet of a mass spectrometer, and charged to 3.5-4.5 kV. Analyte solutions were then applied to the surface, initiating ionization events. Analytes including peptides and small molecule pharmaceuticals were studied in 0.1% formic acid in methanol/water ("spray solvent") as well as in synthetic biological fluid matrices, using both EAP spray ionization (EAPSI) and paper spray ionization (PSI). Each EAPSI analysis required as little as 0.1 μL of solution, and the resulting sprays were stable and reproducible. The sensitivity, limit of detection (LOD), and limit of quantification (LOQ) were evaluated using bradykinin, cannabinol, and cannabidiol, which were prepared in pure solvents, artificial urine, and artificial saliva. The limits of detection and quantitation for EAPSI were improved relative to PSI by 1-2 orders of magnitude for analytes prepared in methanol/water and on the same order of magnitude as PSI for analytes prepared in artificial saliva and urine. This EAP-based spray ionization technique offers possibilities for rapid MS analysis with small sample sizes, high accuracy, and miniaturization of MS instruments.

Noncovalent functionalization of boron nitride via chelation of tannic acid with Fe ions for constructing high thermally conductive polymeric composites

AbstractWith the advancement of integration and miniaturization of precise instruments, the heat accumulating in electronic components is urgently needed to dissipate for ensuring their service life. In this work, boron nitride (BN) was functionalized with tannic acid/ferric ions (TA/Fe) chelate complexes to synthesize high thermally conductive natural rubber (NR) composites (NR@TA/Fe‐BN). The stable TA/Fe chelate complexes improved the interfacial compatibility between BN and NR and enhanced the BN dispersion in the NR matrix, which led to the reduction of interfacial thermal resistance and the construction of heat transfer channels in NR composites. As a result, a relative high thermal conductivity (0.327 W/(mK)) by 30 vol% NR@TA/Fe‐BN composite was achieved, being 2.44 times that of pure NR (about 0.134 W/(mK)). In addition, the insulating NR@TA/Fe‐BN composites showed outstanding elongation at break (686%) and tensile strength (15.2 MPa). This highly efficient and green TA inspired modification is expected to find application in industrial manufacturing of thermally conductive polymeric composites.

Comparison between standard, mini and ultra-mini percutaneous nephrolithotomy for single renal stones: a prospective study.

Based on the current trend of miniaturization of instruments used in percutaneous nephrolithotomy (PCNL), it is necessary to compare different PCNL modalities regarding their access sheath size used. Thus, the safety and efficacy among standard, mini and ultra-mini PCNL (s-PCNL, m-PCNL, um-PCNL) were compared. We performed a prospective, non-randomized trial between January 2018 and July 2020. Patients with stones classified as Guy's stone score grade I were included. The set-up for s-PCNL and m-PCNL included a 30Fr and 22Fr percutaneous tract, respectively. In both set-ups, an ultrasonic/ballistic lithotripter was utilized. In the case of um-PCNL, a 12Fr percutaneous tract was established. A high-power laser was used for lithotripsy. Hemoglobin drop, complication rate, length of hospital stay (LOS), stone-free rate (SFR) and operation time were evaluated. A total of 84 patients, 28 patients per method, were evaluated. Hemoglobin drop was higher in the s-PCNL group when compared to m-PCNL (p = 0.008) and um-PCNL groups (p < 0.001), while um-PCNL group had the slightest hemoglobin drop. LOS was similar between s-PCNL group and m-PCNL group, but um-PCNL group required shorter hospital stay than the other two modalities (p < 0.001). The complication and transfusion rates as well as SFR did not differ between groups. Operation time in the um-PCNL set-up was longer compared to s-PCNL (p < 0.001) and m-PCNL (p = 0.011), whereas s-PCNL and m-PCNL did not differ significantly. m-PCNL showed less hemoglobin drop, but similar operation time and SFR when compared to s-PCNL. um-PCNL showed even less hemoglobin drop, but the operation time was longer compared to the two other modalities.

Crossing Total Occlusions Using a Hydraulic Pressure Wave: Development of the Wave Catheter.

With the ongoing miniaturization of surgical instruments, the ability to apply large forces on tissues for resection becomes challenging and the risk of buckling becomes more real. In an effort to allow for high force application in slender instruments, in this study, we have investigated using a hydraulic pressure wave (COMSOL model) and developed an innovative 5F cardiac catheter (L = 1,000 mm) that allows for applying high forces up to 9.0 ± 0.2 N on target tissues without buckling. The catheter uses high-speed pressure waves to transfer high-force impulses through a slender flexible shaft consisted of a flat wire coil, a double braid, and a nylon outer coating. The handle allows for single-handed operation of the catheter with easy adjusting of the input impulse characteristic, including frequency (1–10 Hz), time and number of strokes using a solenoid actuator, and easy connection of an off-the-shelf inflator for catheter filling. In a proof-of-principle experiment, we illustrated that the Wave catheter was able to penetrate a phantom model of a coronary Chronic Total Occlusion (CTO) manufactured out of hydroxyapatite and gelatin. It was found that the time until puncture decreased from 80 ± 5.4 s to 7.8 ± 0.4 s, for a stroke frequency of 1–10 Hz, respectively. The number of strikes until puncture was approximately constant at 80 ± 5.4, 76.7 ± 2.6, and 77.7 ± 3.9 for the different stroke frequencies. With the development of the Wave catheter, first steps have been made toward high force application through slender shafts.

ACEstat: A DIY Guide to Unlocking the Potential of Integrated Circuit Potentiostats for Open-Source Electrochemical Analysis.

Miniaturization of analytical instrumentation is paramount to enabling convenient in-field sensing. The recent thrust in potentiostat miniaturization for electrochemical sensing and general use has led to the development of commercial application specific integrated circuits (ASICs) that pack all the power of a benchtop instrument into one 5 mm × 5 mm chip. While the capabilities of these integrated circuits far exceed those of open-source potentiostats in the literature, the activation barrier for their implementation requires extensive electrical and software engineering expertise to overcome. In order to more rapidly bring the utility of ASIC potentiostats to researchers, we present a low size, weight, power, and cost (Low SWaP-C) Army Corps of Engineers potentiostat (ACEstat) based on the widely available ADuCM355 offered by Analog Devices. This potentiostat is a streamlined and fully programmable device that leverages industry-leading integrated hardware to perform electrochemical measurements such as cyclic voltammetry, pulse voltammetry, and electrochemical impedance spectroscopy. The ACEstat enables control over a wide range of test parameters and displays results through an intuitive, open-source graphical user interface available on mobile devices and computers. In this report, we present an approachable, do-it-yourself guide to unlocking the capabilities of this integrated circuit potentiostat by outlining the fabrication and programming details necessary to facilitate electroanalysis. Furthermore, we demonstrate the practicality of this device by detecting 2,4,6-trinitrotoluene (TNT) in water at sub-mg/L detection limits, highlighting its potential for in-field use.

An Optical Interferometry Based MEMS Accelerometer Applicable to Seismic-Grade Measurement

Traditional seismometers and gravimeters normally have large volumes and entail high manufacturing costs. Aiming at the miniaturization of such geophysical instruments, a portable Micro-electro-mechanical Systems (MEMS) accelerometer applicable to seismic-grade measurements is fabricated and characterized in this work. This accelerometer is operating on the deformable grating-based MEMS interferometer, where a new MEMS out-of-plane sensing chip employing double layers of 10 &#x03BC;m-thickness spring is first proposed. The simulation results show that this geometry has a low natural frequency of 52.23 Hz and undergoes a low stress of 26.94 Mpa under the gravitational acceleration. The test of the fabricated prototype is implemented in a quiet environment for tracking the inherent micro seismic peaks of Earth. The evaluation results demonstrate that the fabricated prototype has achieved a voltage sensitivity of 510.6 V/g. Furthermore, the noise estimation indicates that the self-noise of this sensor has reached 20 ng/&#x221A;<i>Hz</i> from 0.3 Hz to 20 Hz, and a bias stability of 235.4 ng is obtainable at room temperature. Combined with the compact package size of 40.5 cm³, the proposed device exhibits a promising prospect in the seismic-grade applications.

Feasibility of pocket-sized near-infrared spectrometer for the prediction of cheese quality traits

This study aimed to evaluate the feasibility of a low-cost pocket-sized near-infrared spectrometer (NIR; 740–1070 nm) to predict cheese total nitrogen (%), soluble nitrogen (%), ripening index (%), major minerals (g/100 g of cheese), and fatty acids (g/100 of cheese). A total of 104 ground cheeses samples were scanned 5 times with a pocket-sized NIR and matched with the reference data to develop the prediction models. Modified partial least squares regressions were developed and parameters were optimized through a leave one out cross-validation. Models were validated using 13-fold nested cross validation. The best models were obtained for total fatty acids (ratio of prediction to deviation, RPD = 6.61) and total nitrogen (RPD = 5.95) content. Regarding mineral content, best prediction models were obtained for P (RPD = 4.04), Na (RPD = 3.12), and Ca (RPD = 2.77). Main individual fatty acids and fatty acid groups were poorly predicted, except for SFA (RPD = 2.92), C16:0 (RPD = 2.83), and C4:0 (RPD = 2.51). However, the accuracy of the models was similar to those obtained with benchtop infrared devices. Thus, these results demonstrated that miniaturization of the NIR instruments represents an opportunity in the dairy industry.

Sub-micrometer direct laser writing using an optimized binary-amplitude zone plate lens.

Direct laser writing (DLW) is a versatile and reliable lithography method widely used in many micro and nano fabrication areas. However, the resolution of DLW is limited by the optical diffraction limit. Many methods have been proposed to improve the lithography resolution, but with either high cost or increasing the complexity of the system. Here, we propose a high numerical aperture binary-amplitude-type zone plate lens that can achieve a sub-wavelength focal spot with a large depth of focus and long working distance. The critical dimension of such a lens is set at micrometer scale for ease of fabrication. By integrating the as-designed planar lens into a DLW system, we experimentally demonstrate less than 300 nm lithography resolution with exposure depth larger than 500 nm. Our results show the possibility of writing sub-micrometer scale structures with the integration of a planar lens into the DLW system, which enables miniaturization and compactness of lithography instruments for many applications.

New applications of ultrasound-based muscle activity sensing for rehabilitation engineering

Traditionally, electromyography using surface electrodes has been the dominant method for sensing muscle activity. Major challenges with surface electromyography include the difficulty in resolving signals from overlying muscles and low signal to noise ratio. In recent years, ultrasound has been investigated as an alternative and complementary modality for sensing functional muscle activity that overcomes several limitations of surface electromyography. Ultrasound imaging can non-invasively resolve individual muscles, including deep and overlying muscles, and detect dynamic activity within different functional compartments in real-time. While the use of ultrasound in the biomechanics community has a long history, the continuing miniaturization of ultrasound instrumentation has opened up new opportunities for using ultrasound in rehabilitation engineering as a biosignal sensing modality for assistive devices. This talk will describe results from our current work on developing miniaturized low-power ultrasound instrumentation for wearable systems, including next generation prostheses and exoskeletons. I will also describe opportunities and limitations for applications of ultrasound in rehabilitation engineering.