Monolithic Array Research Articles

Practical Verification of Smart Contracts using Memory Splitting

SMT-based verification of low-level code requires modeling and reasoning about memory operations. Prior work has shown that optimizing memory representations is beneficial for scaling verification—pointer analysis, for example can be used to split memory into disjoint regions leading to faster SMT solving. However, these techniques are mostly designed for C and C++ programs with explicit operations for memory allocation which are not present in all languages. For instance, on the Ethereum virtual machine, memory is simply a monolithic array of bytes which can be freely accessed by Ethereum bytecode, and there is no allocation primitive. In this paper, we present a memory splitting transformation guided by a conservative memory analysis for Ethereum bytecode generated by the Solidity compiler. The analysis consists of two phases: recovering memory allocation and memory regions, followed by a pointer analysis. The goal of the analysis is to enable memory splitting which in turn speeds up verification. We implemented both the analysis and the memory splitting transformation as part of a verification tool, CertoraProver, and show that the transformation speeds up SMT solving by up to 120x and additionally mitigates 16 timeouts when used on 229 real-world smart contract verification tasks.

Charge Sharing Assessment and Active Collimation in Monolithic Arrays of Silicon Drift Detectors

Charge Sharing Assessment and Active Collimation in Monolithic Arrays of Silicon Drift Detectors

Monolithic linear array fiber end cap for spectral beam combination

In this study, a fusion splicing system that facilitates the splicing of a monolithic linear array fiber end cap is constructed. The fusion splicing thermal field of the end cap irradiated by a CO2 laser is theoretically simulated using the finite element method. The experimental fusion splicing temperature agrees well with the simulation results. The splicing strength, misalignment, and high-power withstanding capacity of the fusion-spliced monolithic linear 3-fiber end cap are investigated. The use of the fabricated device in a dual-grating spectral beam combination (SBC) is also demonstrated with three-channel laser beams, achieving a combined beam with near-diffraction-limited beam quality M2=1.101. It shows that the development of the monolithic linear array fiber end cap is meaningful for achieving a compact high-brightness SBC system.

Thiol-functionalized MOF modified 3D printed monolithic microextraction array for analysis of trace Cd and Pb in human urine

Controlling the position, size, and shape of pores is a limitation of traditional monolithic preparation methods. The application of 3D printing technology offers high customizability, allowing the precise printing of pore positions, sizes, and shapes according to the designer's 3D model. Herein, by using Projection Microstereolithography (PμSL), we prepared a 3D-printed monolithic array with post-modification of thiol-functionalized metal-organic framework (MOF), and combined it with inductively coupled plasma mass spectrometry (ICP-MS) for the online analysis of trace Cd and Pb in human urine. To achieve array monolithic microextraction, six 3D-printed monolithic columns were modified with thiol-functionalized MOF-808 (MOF-808-SH), and were then assembled in the 3D printed extraction device incorporating gas valve and scaffold. The MOF-808-SH modified 3D-printed monolithic column exhibits excellent extraction performance to Cd2+ and Pb2+ due to rich active adsorption sites and hierarchical porous structure, and has long life span (>100 reused times). Under the optimized conditions, the limits of detection (LODs) are 3.5 and 17.6 ng L−1 for Cd2+ and Pb2+, respectively, with the relative standard deviations of 4.9 % and 8.2 % (0.1 μg L−1, n = 7), and the sample throughput is 11 h−1. To validate the accuracy of the method, the method was used to determine Cd and Pb in Certified Reference Materials of freeze-dried human urine, the determined results agree well with the certified values. This method was also successfully applied to the determination of trace Cd and Pb in real human urine samples. The developed method offers low LODs, robust anti-interference capability, high sample throughput, long reuse cycles, and automation analysis, showing great potential for the analysis of trace heavy metals in biological samples.

Development of high-efficiency X-ray detectors based on 1 mm thick monolithic SDD arrays

We present the novel 2× 4 monolithic Silicon Drift Detectors (SDD) array of 1 mm thickness developed within the context of the SIDDHARTA-2 experiment for high-energy X-ray spectroscopy measurements of light kaonic atom transitions. It represents a state-of-the-art advancement in terms of detection efficiency with respect to the previous generation of detectors, having a thickness of 450 μm. The sensor features eight square SDD units with an active area of 8 × 8 mm2 each, arranged in a 2 × 4 matrix. Therefore, the total active area of the array is 32 × 16 mm2 while the total chip area is 36 × 20 mm2, including a 2-mm dead region on each side of the array. This new version of SDD arrays, manufactured by Fondazione Bruno Kessler (FBK), includes an additional electrode on its entrance window, designed to reduce charge sharing between adjacent channels and improve energy resolution. This article describes two different detection modules based on these arrays: the first module includes a single array, whereas the second one is composed of two 1 mm thick SDD arrays in a stacked configuration, in order to reach 2 mm of effective thickness and further increase the module detection efficiency. The first spectroscopic measurements obtained with the two modules will be also reported in the paper, showing the spectroscopic improvements that can be obtained with the additional electrode on the window and the efficiency improvements that can be obtained with the stacked module.

Mechanism of formation and evolution of bound states in the continuum of split-hole all-dielectric metasurface under asymmetric displacement perturbation

Bound states in the continuum (BICs) with ultra-high Q properties have attracted much attention for their perfect localization in the continuous spectral range coexisting with extended waves. In this study, breaking the traditional excitation form of structure breakage or excitation field asymmetry, a monolithic silicon nanodisk array with relative displacement generated by the complete splitting of square nanopores is proposed based on the unique electromagnetic properties of all-dielectric metamaterials. During the introduction of perturbations by asymmetric displacements of splitting holes, it is shown by numerical simulations that two BICs at different wavelengths can be realized. Combined with eigenmodes of group theory, the symmetric matching relationship between the symmetry-protected BICs and the free-space radiation during the evolution process is analytically demonstrated, and the formation mechanism and the evolution law of the BICs excited by this metasurface are deeply investigated. meanwhile, it also provides a theoretical basis for the polarization dependence of quasi-BICs excitation and the ultra-high Q factor expression of BICs. Furthermore, near-field distribution and multipole decomposition show that the field distribution and surface currents support the excitation of BIC-driven toroidal dipole and magnetic quadrupole dual modes. This study not only provides an effective reference for the stability of high-Q resonance wavelengths, but also solves the problem of the lack of universality in analyzing the resonance mechanism based on resonance phenomena, and provides solid theoretical support for the study of displacement-mediated BICs resonance excitation and evolution.

Radiation Properties of Two Elements Microstrip Antenna Array at Microwave Frequencies

One of the key challenges in developing radio communication systems is the creation of tiny solid-state radiation sources, particularly in the microwave and millimeter range.An antenna serves as the efficient interface between electronic circuits and the external environment, making it a crucial element in the growing trend of using high frequencies in contemporary wireless communications.The card actively contributed to the development of several subsystems for an active monolithic Phased Array Antenna, which utilizes solutions in space technology and antenna technologies operating at frequencies of around 30 GHz and 28 GHz, such as Local Multipoint Distribution (LMDS). This document primarily focuses on the study method and the two components of active patch arrays. The radiation models were computed utilizing the cavity plate model, the Simple Green model, and the rigorous commercial Electromagnetic Simulator. The active rectangular patches with the Gann diode were reconfigured and assembled into arrays in the E-plane and H-plane. The calculated and measured findings for both active arrays have proved the potential for beam scanning. All three models have accurately projected radiation levels across a wide range of steering controls. To ensure stable operation, a thin dielectric layer was positioned in front of the H plane of the array. The impact of the dielectric layer on the even and odd modes of the array has been demonstrated.

Tuning the Interfacial Chemistry of Nanoparticle Assemblies via Spin‐Coating: From Single Sensors to Monolithic Sensor Arrays

AbstractSensor arrays based on gold nanoparticle (GNP) films are promising candidates for numerous applications, including medical diagnosis and health monitoring. Their economic fabrication, however, remains challenging. This study presents a facile route to GNP chemiresistors with tunable properties via layer‐by‐layer spin‐coating (LbL‐SC). Key steps involve the alternating deposition of dodecylamine‐stabilized GNPs and mixtures of monothiols (MTs) with 1,9‐nonanedithiol (9DT). The 9DT molecules serve to reinforce the growing film via GNP cross‐linking while the MT ligands are used to tune the interfacial chemistry of the GNP assembly. Hence, by employing differently functionalized MTs the sensors' chemical selectivity can easily be adjusted. Further, by varying the MT‐9DT ratio and adjusting the size of the MT ligands the sensitivity can be tuned along with the conductivity and optical properties of the films. In general, decreasing the 9DT fraction significantly enhances the sensitivity while the response isotherms change from Langmuir‐Henry to Henry type. Finally, the cross‐linked GNP films are robust enough to be patterned via photolithography. Hence, this study demonstrates the fabrication and application of monolithic sensor arrays. Different features of the responses to numerous analytes are used as input data for linear discriminant analyses (LDA), revealing that very similar analytes can be distinguished.

The Data Analysis of BULLKID: A Monolithic Array of Particle Absorbers Sensed by KIDs

The Data Analysis of BULLKID: A Monolithic Array of Particle Absorbers Sensed by KIDs

Monolithic beam combined quantum cascade laser arrays with integrated arrayed waveguide gratings.

Quantum cascade lasers (QCLs) are ubiquitous mid-infrared sources owing to their flexible designs and compact footprints. Manufacturing multiwavelength QCL chips with high power levels and good beam quality is highly desirable for many applications. In this study, we demonstrate an λ ∼ 4.9 µm monolithic, wavelength beam-combined (WBC) infrared laser source by integrating on a single chip array of five QCL gain sections with an arrayed waveguide grating (AWG). Optical feedback from the cleaved facets enables lasing, whereas the integrated AWG locks the emission spectrum of each gain section to its corresponding input channel wavelength and spatially combines their signals into a single-output waveguide. Our chip features high peak power from the common aperture exceeding 0.6 W for each input channel, with a side-mode suppression ratio (SMSR) of over 27 dB when operated in pulsed mode. Our active/passive integration approach allows for a seamless transition from the QCL ridges to the AWG without requiring regrowth or evanescent coupling schemes, leading to a robust design. These results pave the way for the development of highly compact mid-IR sources suitable for applications such as hyperspectral imaging.

Multilayer printed antennas and arrays for 5G applications

ABSTRACT In this paper we describe a class of printed patch antennas that involve 3 metal layers completely integrated within a single dielectric, which are of very high efficiency and significant gain. The antennas presented have dual linear polarization and sufficient impedance matching bandwidth to be suited for sub-6 5G applications, producing advantageous antenna arrays monolithically integrated into a single planar PCB that are thin and lightweight. The feeding mechanism of the antennas is through an intermediate dedicated metal layer designed appropriately as a coupler, coupling the input power at the feeding ports of the structure to the antenna without a direct metal contact to the radiating patch. The multilayer design allows monolithic integration of multi-element combiners and phase shifters within the PCB of antenna arrays and results in compact monolithic scanning arrays. Theoretical full-wave simulations and measurements of fabricated prototypes are in very good agreement and validate the proposed designs.

A continuous ultra-narrow impulse synchronizer using a monolithic field programmable gate array for fast deployment and scalability.

Ultra-narrow pulses serve as critical components in numerous applications. These pulses have ultra-fast leading edges that typically function as precision trigger signals to synchronize various instruments. Ultra-narrow pulses inherently exhibit an ultra-wide bandwidth, gaining significant attention in diverse electronic systems encompassing communications, radar imaging, electronic warfare, and others. Although several techniques have been explored for generating ultra-narrow pulses, field programmable gate arrays (FPGAs) offer a promising alternative in terms of flexibility and integration. This study introduces a scalable delay pulse synchronizer method with a resolution of 23 ps. A programmable, successive, narrow pulse sequence operating at a 1-GHz repetition frequency is implemented within a monolithic FPGA. The performance of the proposed method is evaluated using an existing board with a general commercial FPGA in the laboratory. This new method presents a convenient and efficient approach of achieving ultra-narrow pulse synchronization, being applicable across various fields.

Monolithic silicon microlens arrays for far-infrared astrophysics.

Future far-infrared astrophysics observatories will require focal plane arrays containing thousands of ultrasensitive, superconducting detectors, each of which require efficient optical coupling to the telescope fore-optics. At longer wavelengths, many approaches have been developed, including feedhorn arrays and macroscopic arrays of lenslets. However, with wavelengths as short as 25µm, optical coupling in the far infrared remains challenging. In this paper, we present an approach to fabricate far-infrared monolithic silicon microlens arrays using grayscale lithography and deep reactive ion etching. The fabricated microlens arrays presented here are designed for two different wavebands: 25-40µm and 135-240µm. The microlens arrays have sags as deep as 150µm, are hexagonally packed with a pixel pitch of 900µm, and have an overall size as large as 80 by 15mm. We compare an as-fabricated lens profile to the design profile and calculate that the fabricated lenses would achieve 84% encircled power for the designed detector, which is only 3% less than the designed performance. We also present methods developed for antireflection coating microlens arrays and for a silicon-to-silicon die bonding process to hybridize microlens arrays with detector arrays.

A Novel Monolithic MEMS Array for E-Nose Applications

A Novel Monolithic MEMS Array for E-Nose Applications

Novel sensor developments for photon science at the MPG semiconductor laboratory

The world of photon science experiences significant advancements since the advent of synchrotron light sources with unprecedented brilliance, intensity and pulse repetition rates, with large implications on the detectors used for instrumentation. Here, an overview about the work on this field carried out at the semiconductor laboratory of the Max-Planck-Society (MPG HLL) is given. Main challenges are high dynamic range to resolve faint features at the fringes of scatter images as well as structures in bright peaks, and high bandwidth to fully exploit the fast timing capability of the source. A newly developed device to improve the signal-to-noise-ratio (SNR) at high bandwidths is the so-called MARTHA (Monolithic Array of Reach-Through Avalanche Photodiodes) structure, which integrates an array of APDs on a monolithic substrate. The reach-through architecture assures near 100% fill factor and allows implementing a thin entrance window with optimized quantum efficiency for low energy X-rays. The structures operate in proportional mode with adjustable gain, and can serve as a drop-in replacement for PAD detectors in hybrid pixel systems. A more sophisticated solution for low to medium frame rate applications with high contrast requirement are pnCCDs with high dynamic range in the pixel area featuring DEPFET based readout nodes with non-linear amplification (NLA). The high dynamic range mode has been demonstrated for pnCCD devices with a pixel size down to 75 μm2. Framerates of up to 1 kHz are possible for a 1 Megapixel detector. Small size prototypes of these structures have recently been manufactured. Modified DEPFET structures with build-in non-linear amplification are also used to implement active pixel detectors optimized for high dynamic range. Successfully prototyped for the DSSC sensors (DEPFET Sensor with Signal Compression) at the XFEL, these structures are increasingly being used in applications requiring high contrast and intensity, e.g., TEM imaging. Charge handling capability and output characteristics can be tailored to the requirements, as well as pixel geometry and size. The large intrinsic gain of the DEPFET provides excellent SNR even at fast timing. Pixels can be read with a speed of 100 ns, the resulting frame rate depends on the degree of readout parallelization.

Ultrasensitive sensing urinary cystatin C via an interface-engineered graphene extended-gate field-effect transistor for non-invasive diagnosis of chronic kidney disease

Early chronic kidney disease (CKD) has strong concealment and lacks an efficient, non-invasive, and lable-free detection platform. Cystatin C (Cys C) in urine is closely related to the progress of CKD (especially at the early stage), which is an ideal endogenous marker to evaluate the impairment of renal function. Thus, the accurate detection of urinary Cys C (u-Cys C) is great significant for early prevention and treatment and delaying the course of the disease of CKD patients. Herein, we developed an extended-gate field-effect transistor (EG-FET) sensor for ultrasensitive detection of u-Cys C, which consists of a monolithic interface-engineered graphene EG electrode array and a commercially available MOSFET. Laser-induced graphene (LIG) loaded with sputtered Au NPs in the presence of adhesive Cr (Au NPs/Cr/LIG) boosts the electrical performance of the EG electrode. Meanwhile, Au NPs also serve as linkers to immobilize papain that can selectively form protein complexes with Cys C. Supported by the synergistic effect of multilevel interface-engineered graphene, our sensor exhibits a good linear correlation within the u-Cys C concentration range of 5 ag/μL to 50 ng/μL with low detection limit of 0.05 ag/μL. Our work makes accurate, specific and rapid detection of u-Cys C feasible and promising for early screening for CKD.

Metal-decorated 3D tin oxide nanotubes in a monolithic sensor array chip for room-temperature gas identification

Inadequate limit of detection at room temperature and unsatisfactory selectivity remain challenge for wide applications of the chemiresistive gas sensors. Nanostructured gas sensors ensure the desirable activation energy for the gas adsorption and chemical reactions, favorable for room-temperature parts-per-billion (ppb) level gas detection. In this work, we demonstrated a single-chip integrated gas sensor array (4 ×4 pixels) based on kinds of metal (Pt, Pd, Au, Ag) decorated 3D SnO2 nanotubes for ultrasensitive room-temperature gas-sensing. The nanostructured sensor array has a high surface area-to-volume ratio, enabling room temperature sensing with high detection response toward H2 (minimum 5 ppm), formaldehyde (minimum 50 ppb), toluene (minimum 50 ppb) and NO2 (minimum 100 ppb) with the detection accuracy within 5% range, respectively. In addition, the effect of metals decoration on the gas identification features were systematically conducted, and these specific response features can be mainly attributed to metal activation capability toward the gases, which enables demonstrating differentiable response patterns for the target gases identification employing a pattern recognition algorithm. These results demonstrate that the proposed strategy helps to provide an excellent route for the future low-power-consumption smart sensing devices design and fabrication.

Soft-template-assisted bottom-up fabrication of tunable porosity monolithic copper film for interconnection in microelectronics

Background: Third-generation devices offer superior attributes, necessitating advanced packaging materials for harsh operating environments. Incorporating 3D porous architectures to increase the reaction area further enhances the reaction rate, making transient liquid phase bonding an ideal interconnection process. Methods: Fabrication of monolithic porous Cu films using a bicontinuous microemulsion (BME) as a dynamic soft template is reported. The BME phase consists of interconnected three-dimensional networks of aqueous and oil phases, separated by surfactants and cosurfactants. This unique structure enables the selective electrodeposition of Cu exclusively within the aqueous region, preventing any unwanted reactions in the oil phase. Tunable porosity in the monolithic Cu film is achieved by adjusting the water to oil phase ratio in the BME. Significant findings: The Sn-plated porous Cu films exhibit low-temperature reflow capability while still maintaining high service temperatures. The utilization of the BME soft template offers a promising approach for fabricating monolithic Cu films with tunable porosity, providing flexibility in controlling the compositions and performance of interconnections. The compatibility of the BME with existing wafer deposition techniques makes it a viable and scalable solution for mass production. The electrodeposition of monolithic Cu arrays on Cu pillars demonstrates its potential applicability in advanced packaging technologies.

V-Band Monolithic Additive-Manufactured Geodesic Lens Array Antenna

V-Band Monolithic Additive-Manufactured Geodesic Lens Array Antenna

Nanoprinted Diffractive Layer Integrated Vertical-Cavity Surface-Emitting Vortex Lasers with Scalable Topological Charge.

Vertical-cavity surface-emitting lasers (VCSELs) represent an attractive light source to integrate with OAM structures to realize chip-scale vortex lasers. Although pioneering endeavors of VCSEL-based vortex lasers have been reported, they cannot achieve large topological charges (less than l = 5) due to the insufficient space-bandwidth product (SBP) caused by the inherent limited device size. Here, by integrating a nanoprinted OAM phase structure on the VCSELs, we demonstrate a vortex microlaser with a low threshold and simple structure. A monolithic microlaser array with addressable control of vortex beams with different topological charges (l = 1 to l = 5) was achieved. Nanoprinting offers high degrees of freedom for the manipulation of spatial structures. To address the challenge of insufficient SBP, two-layer cascaded spiral phase plates were designed. Thereby, a vortex beam with l = 15 and mode purity of 83.7% was obtained. Our work paves the way for future chip-scale OAM-based information multiplexing with more channels.