2D Array Research Articles

High-Volume Production of Repeatable High Enhancement SERS Substrates Using Solid-State Superionic Stamping

Abstract Surface-enhanced Raman spectroscopy (SERS) is emerging as a powerful tool for detecting and identifying chemical and biological substances because of its high sensitivity, specificity, speed, and label-free detection. For SERS substrates to be effective in sensing applications, they must exhibit reproducible and robust high signal enhancement and cost-effective scalability. This article introduces a highly sensitive, large-area silver SERS substrate patterned with a uniform array of 3D retroreflecting inverted pyramids and develops a manufacturing pathway for it, using a novel and facile electrochemical imprinting process called solid-state superionic stamping (S4). Substrates, approximately 4 mm2 in area, are produced and tested with 1,2-bis(4-pyridyl) ethylene (BPE). Uniformly high and reproducible spatially averaged enhancement factor (EF), typically around a value of 2 × 107 with a relative standard deviation of 6.7% and a high batch-to-batch repeatability with a relative standard deviation of 10.5% between batches were observed. Passivating a substrate's surface with atomically thin layers of alumina, deposited using atomic layer deposition (ALD) was effective in maintaining the EF constant over a 60-day period, albeit with a trade-off between its EF and its lifespan. S4 has the potential to make substrates with EF consistently greater than 107 available at a cost of $1 to $2 per substrate, allowing SERS to be adopted across a wide spectrum of high-volume applications, including security, food safety, medical diagnostics, and chem-bio analysis.

Pico-ampere resolution current measurement circuit using Gm-C filter sigma-delta modulator for low-power nanopore DNA sequencing

New generation DNA sequencers use an array of electrochemical cells equipped with nanopores, which produce pico-ampere current levels. Due to the large number of channels, low current levels and bandwidths in the order of a few kHz, in the design of these readout circuits, 2D arrays of in-channel, low noise and low power analog to digital converters are preferred. Previously many different sigma-delta modulators have been presented to convert the nanopore current signal into a digital code. Conventionally, the opamps required in these converters will eventually increase the power dissipation of each channel. In this paper a novel Gm-C filter based second order sigma-delta converter is proposed. In the given design, rather than relying on multiple opamps to achieve the necessary gain and noise performance, only a 4 transistor Gm block is used. Evaluations show that while the input referred noise remains close to previous methods, the power dissipation is considerably reduced. A prototype is also implemented to show the effectiveness of the approach. In a 180-nm design, an ENOB of 12.16 bits, RMS input referred noise of 0.2 pA at 10 kHz bandwidth and power dissipation of 8.27 μW is obtained per channel.

An innovative approach to 2D localization using the magnetic shielding effect

The effect on an electromagnetic field when a low-cost magnetically permeable object such as copper or aluminum is placed within it can be observed to determine the object’s location. This approach offers a novel technique to achieve reliable localization, particularly in environments where line of sight sensing methods may be non-applicable. Shields up to a size of 30×30 mm and a thickness of 80 µm were investigated; copper shields of these dimensions reduced the signal strength to 91 %, and aluminum shields reduced the signal strength to 94 % of its initial strength. The distortions to the electromagnetic field were closely related to the location of the tag. By fitting an inverted Gaussian curve to each sensor’s data, the position of a shield along a line could be predicted. This method can be used to locate a tag within a 2D plane by creating a 2D array of sensors beneath the sensing plane.

3D Lightweight Cryptosystem Design For IoT Applications Based On Composite S-Box

The security of the Internet of Things (IoT) depends on strong cryptographic functions that require extensive computation and resources. The security of Internet of Things (IoT) relies on the use of strong cryptographic functions that demand extensive computation and resources. Therefore, the selection of a cryptographic system is influenced by the computational and communicational capabilities of IoT devices, including their energy requirements, memory constraints, and execution time. This paper aims to develop a lightweight and secure encryption algorithm for IoT applications, focusing on advancing cryptanalysis techniques. We propose a new lightweight algorithm named enhanced 3D RECTANGLE, designed to deliver robust security for IoT applications and optimized for cell phones with minimal memory usage, low power consumption, and efficient performance. The RECTANGLE block cipher was chosen for this research due to its high efficiency and speed relative to other lightweight algorithms, despite some security issues. The proposed enhanced 3D RECTANGLE algorithm improves confusion and diffusion properties through a new 3D array block rotation method for 4x4 plaintext, based on a 128-bit key and 16 rounds. Additionally, we designed a 4x4 composite S-Box with a Galois field pipelining structure, offering a more advanced solution compared to the Look-Up Table method. The cryptanalysis, avalanche effect, and bit error rate tests were conducted to verify the security strength of the proposed algorithm. The proposed algorithm was evaluated against two existing algorithms, RECTANGLE and Extended 3D RECTANGLE. The enhanced 3D RECTANGLE algorithm provides better cryptanalysis, demonstrating a 40% avalanche effect and achieving a bit error rate (BER) of 31%, indicating its greater effectiveness compared to the other two lightweight algorithms.

Shaping the RF Transmit Field in 7T MRI Using a Nonuniform Metasurface Constructed of Short Conducting Strips.

The ability of metamaterial structures to offer unique properties and new solutions has opened new avenues in a wide range of applications, including super-resolution in optics and efficient antennas in radiofrequency (RF) engineering. In magnetic resonance imaging (MRI), metamaterials hold the promise of increasing the RF magnetic field intensity while minimizing power deposition. Here, we propose a metasurface based on a two-dimensional (2D) array of short conducting strips combined with a high dielectric substrate, which was tuned to operate at ultrahigh field 7T human MRI. While studied in optics and electromagnetics in the GHz-to-THz range, this study is the first to design such a metasurface for proton imaging at 7T MRI. We performed electromagnetic (EM) simulation of the brain MRI setup with the new metasurface placed in the proximity to the temporal lobe, which showed 2.2-fold local increase in the RF transmit efficiency, with superior performance than an array of electric dipoles. In this study, we also investigate the effect of the spatial distribution of the subunits to control the target RF field's distribution. While the common design is based on a uniform distribution of the subunits, nonuniform distribution, such as a denser center (convex) or more condensed edges (concave), provides an extra dimension to tailor both the magnetic and electric fields. The concave distribution achieved 1.5-1.8-fold reduction in the power deposition compared to the uniform distribution in the brain MRI setups examined.

Investigation of the linear accelerator low dose rate mode for pulsed low-dose-rate radiotherapy delivery

Purpose. Pulsed volumetric modulated arc therapy (VMAT) was proposed as an advanced treatment that combines the biological benefits of pulsed low dose rate (PLDR) and the dosimetric benefits of the intensity-modulated beams. In our conventional pulsed VMAT technique, a daily fractional dose of 200 cGy is delivered in 10 arcs with 3 min intervals between the arcs. In this study, we are testing the feasibility of pulsed VMAT that omits the need to split into ten arcs and excludes any beam-off gaps. Methods. The study was conducted using computed tomographic images of 24 patients previously treated at our institution with the conventional PLDR technique. Our newly installed Elekta machine has a low dose rate option on the order of 25 MU min−1. PLDR requires an effective dose rate of 6.7 cGy min−1 with attention being paid to the maximum dose received within any point within the target not to exceed 13 cGy min−1. The quality of treatment plans was judged based on dose-volume histograms, isodose distribution, dose conformality to the target, and target dose homogeneity. The dose delivery accuracy was assessed by measurements using the MatriXX Evolution 2D array system. Results. All cases were normalized to cover 95% of the target volume with 100% of the prescription dose. The average conformity index was 1.03 ± 0.08 while the average homogeneity index was 1.05 ± 0.02. The maximum reported dose rate at any point within the target was 10.44 cGy min−1. The mean dose rate for all pulsed VMAT plans was 6.88 ± 0.1 cGy min−1. All cases passed our gamma analysis with an average passing rate of 99.00% ± 0.48%. Conclusion. The study showed the applicability of planning pulsed VMAT using Eclipse and its successful delivery on our Elekta linac. Pulsed VMAT using the machine’s low dose rate mode is more efficient than our previous pulsed VMAT delivery.

3D height-alternant island arrays for stretchable OLEDs with high active area ratio and maximum strain

Stretchable optoelectronic devices are typically realized through a 2D integration of rigid components and elastic interconnectors to maintain device performance under stretching deformation. However, such configurations inevitably sacrifice the area ratio of active components to enhance the maximum interconnector strain. We herein propose a 3D buckled height-alternant architecture for stretchable OLEDs that enables the high active-area ratio and the enhanced maximum strain simultaneously. Along with the optimal dual serpentine structure leading to a low critical buckling strain, a pop-up assisting adhesion blocking layer is proposed based on an array of micro concave structures for spatially selective adhesion control, enabling a reliable transition to a 3D buckled state with OLED-compatible processes. Consequently, we demonstrate stretchable OLEDs with both the high initial active-area ratio of 85% and the system strain of up to 40%, which would require a lateral interconnector strain of up to 512% if it were attained with conventional 2D rigid-island approaches. These OLEDs are shown to exhibit reliable performance under 2,000 biaxial cycles of 40% system strain. 7 × 7 passive-matrix OLED displays with the similar level of the initial active-area ratio and maximum system strain are also demonstrated.

A singlet-triplet hole-spin qubit in MOS silicon

Holes in silicon quantum dots are promising for spin qubit applications due to the strong intrinsic spin-orbit coupling. The spin-orbit coupling produces complex hole-spin dynamics, providing opportunities to further optimise spin qubits. Here, we demonstrate a singlet-triplet qubit using hole states in a planar metal-oxide-semiconductor double quantum dot. We demonstrate rapid qubit control with singlet-triplet oscillations up to 400 MHz. The qubit exhibits promising coherence, with a maximum dephasing time of 600 ns, which is enhanced to 1.3 μs using refocusing techniques. We investigate the magnetic field anisotropy of the eigenstates, and determine a magnetic field orientation to improve the qubit initialisation fidelity. These results present a step forward for spin qubit technology, by implementing a high quality singlet-triplet hole-spin qubit in planar architecture suitable for scaling up to 2D arrays of coupled qubits.

A 3D photon-to-digital converter readout for low-power and large-area applications

A new trend in large area noble liquid experiments is to measure the scintillation light with photodetectors and their electronics inside the active volume. Compared to the typical approach of using silicon photomultipliers (SiPM) with an analog readout chain leading to an analog-to-digital converter, this paper presents a new 3D photon-to-digital converter (PDC) readout that takes advantage of the binary nature of the single-photon avalanche diodes (SPAD). The readout contains 4096 pixels over 25 mm2, each including a 3D bonding pad and a quenching circuit. The readout features three different outputs: a fast flag to get the timestamp of each event from an external time-to-digital converter, a digital sum to retrieve the number of pixels triggered during an event, and an analog monitor to generate an analog SiPM-like output. The analog monitor is also used to validate the two former digital outputs. The readout also includes 61 2D CMOS SPADs for validation purpose prior to the final 3D integration with SPADs custom made according to our design by Teledyne DALSA (Bromont, Canada). As a first system integration toward large-area detector applications, a mini-tile of 2 × 2 readouts has been developed to test all the functionalities. The measured single-photon timing resolution ranges from 72 to 93 ps FWHM across the mini-tile SPAD channels population (i.e. 4 × 61 channels). The flag timing resolution is below 95 ps RMS, which includes the contribution of the optimized flag H-tree but also an additional trigger tree that replaces the 3D SPAD array at this stage of development. Once bonded with the 3D SPADs, the trigger tree won't be required to measure the flag timing resolution. With the removed contribution of the trigger tree, the estimated flag timing resolution should be below 45 ps RMS. The extent of the benefits of the digital sum output depend on the application, and this paper focuses on two cases. First, a low-power coincidence scheme such as required by the nEXO liquid xenon experiment, leading to a power consumption as low as 140 μW per PDC. With a finer sampling of the scintillation light such as required for pulse shape discrimination in liquid argon, the power consumption remains below 100 μW per PDC. Overall, this readout is designed as a replacement for a typical analog SiPM chain, without compromise on the performances.

Experimental demonstration of a silicon nanophotonic antenna for far-field broadened optical phased arrays

Optical antennas play a pivotal role in interfacing integrated photonic circuits with free-space systems. Designing antennas for optical phased arrays ideally requires achieving compact antenna apertures, wide radiation angles, and high radiation efficiency all at once, which presents a significant challenge. Here, we experimentally demonstrate a novel ultra-compact silicon grating antenna, utilizing subwavelength grating nanostructures arranged in a transversally interleaved topology to control the antenna radiation pattern. Through near-field phase engineering, we increase the antenna’s far-field beam width beyond the Fraunhofer limit for a given aperture size. The antenna incorporates a single-etch grating and a Bragg reflector implemented on a 300-nm-thick silicon-on-insulator (SOI) platform. Experimental characterizations demonstrate a beam width of 44°×52° with −3.22 dB diffraction efficiency, for an aperture size of 3.4 μm×1.78 μm. Furthermore, to the best of our knowledge, a novel topology of a 2D antenna array is demonstrated for the first time, leveraging evanescently coupled architecture to yield a very compact antenna array. We validated the functionality of our antenna design through its integration into this new 2D array topology. Specifically, we demonstrate a small proof-of-concept two-dimensional optical phased array with 2×4 elements and a wide beam steering range of 19.3º × 39.7º. A path towards scalability and larger-scale integration is also demonstrated on the antenna array of 8×20 elements with a transverse beam steering of 31.4º.

Noise Scaling in SQUID Arrays

Abstract We numerically investigate the noise scaling in high-T_c commensurate 1D and 2D SQUID arrays. We show that the voltage noise spectral density in 1D arrays violates the scaling rule of ~1/N_p for the number N_p of Josephson junctions in parallel. In contrast, in 2D arrays with N_s 1D arrays in series, the voltage noise spectral density follows more closely the expected scaling behaviour of ~N_s/N_p. Additionally, we reveal how the flux and magnetic field rms noise spectral densities deviate from their expected ~(N_sN_p)^{-1/2} scaling and discuss their implications for designing low noise magnetometers.

Bilayer Crystals of Trapped Ions for Quantum Information Processing

Trapped-ion systems are a leading platform for quantum information processing, but they are currently limited to 1D and 2D arrays, which imposes restrictions on both their scalability and their range of applications. Here, we propose a path to overcome this limitation by demonstrating that Penning traps can be used to realize remarkably clean bilayer crystals, wherein hundreds of ions self-organize into two well-defined layers. These bilayer crystals are made possible by the inclusion of an anharmonic trapping potential, which is readily implementable with current technology. We study the normal modes of this system and discover salient differences compared to the modes of single-plane crystals. The bilayer geometry and the unique properties of the normal modes open new opportunities—in particular, in quantum sensing and quantum simulation—that are not straightforward in single-plane crystals. Furthermore, we illustrate that it may be possible to extend the ideas presented here to realize multilayer crystals with more than two layers. Our work increases the dimensionality of trapped-ion systems by efficiently utilizing all three spatial dimensions, and it lays the foundation for a new generation of quantum information processing experiments with multilayer 3D crystals of trapped ions. Published by the American Physical Society 2024

Efficient magnetic forward modeling for strongly magnetized bodies: An iterative integral equation approach

Magnetic surveying encounters challenges in high-precision detection and inversion on strongly magnetized bodies. Nonuniform magnetization caused by self-demagnetization and mutual magnetization makes magnetic field calculation using analytical formulas impractical. The previous discrete numerical methods have suffered from computational inefficiency or low accuracy. To resolve this issue, we develop an algorithm to solve the magnetic field integral equation for calculating the magnetization state of high-susceptibility bodies, combining the improved spatial convolution forward approach with the adaptive relaxation iteration method. To address the excessive computational burden in the magnetization field between 3D voxel arrays of the discrete model, we construct the circular convolution kernel matrix directly when the subsurface space is divided with an equidistant grid, significantly reducing redundant computations. Then, the fast Fourier transform is used to accelerate the forward discrete circular convolution operation. In addition, we derive an iterative computation scheme that adaptively adjusts the relaxation factor based on magnetic field changes to correct the effective magnetization for algorithm convergence. From a pragmatic perspective, equating the cuboid to equal-volume sphere subdivisions is developed to enhance computational efficiency further by approximately 50% despite sacrificing slight accuracy. The sphere and spherical shell models validate the algorithm accuracy, efficiency, and convergence. Furthermore, we analyze the characteristics of the mutual magnetization effect among magnetic bodies under different magnetization conditions. Finally, the applicability of the algorithm is demonstrated with a realistic example. Our algorithm shows promise for precisely exploring highly magnetized minerals, underground pipelines, and unexploded ordnance.

High Throughput Screening of Electroactive Bacteria Using a Cross-Bar Architecture in a 3D Design Array

Promoting extracellular electron transfer (EET) in bacteria has many widespread applications including wastewater treatment and environmental remediation. With the development of synthetic biology technologies that can alter microbial electron transfer routes and enhance their electrogenic capacity, there is a need for high throughput systems to identify the responsible genes and the consequent metabolic pathways in an expeditious way. Conventional platforms utilizing single electrodes, or electrochemical cells, and colorimetric detection suffer from low sensitivity and low throughput. Moreover, they require bulky equipment for readout and fluid handling. Moving towards a nuanced miniaturized electrochemical detection, we propose individually addressable microwells used to monitor electron flux from EET-capable bacteria with the ability to screen a large number of electroactive bacteria for various applications. Materials and method : The device is simple and fabricated with cost-effective electrodes. Carbon felt is used as the working electrode to improve bacterial entrapment and assist in capturing maximum electrons donated by the electroactive bacteria. Silver-silver chloride ink (Ag/AgCl) as the reference electrode will help maintain the potential of with respect to the working electrode. Conductive carbon ink as the counter electrode will promote current collection. The proposed device has the elements of a traditional three electrode system arranged in two different planes resulting in a 3D configuration of electrodes. The reference and counter electrode are on the bottom plane with acrylic wells housed right above each electrode pair, while the working electrode is used in the cross-bar architecture from the top plane as shown in Figure 1(a). The fabrication steps are illustrated in Figure 1(b). This system can be scaled to have 10000 microwells on a single platform with individual addressability of each micro-well array. With this layout, connections from the innermost wells can be drawn effortlessly without any signal damping from the surrounding wells. As a proof of concept, we have fabricated a 9 by 9 array (20cm by 20 cm) as shown in Figure 1(a). Five strains of Shewanella oneidensis MR-1, the wild type organism and four modified strains overexpressing variants of MtrA (unmodified MtrA, IV-205, IV-261 and an empty vector), were screened for their current producing capacity [1]. Results:A bacterial load of OD600= 0.065 was sufficient to give a reliable current signal. For each strain, the working electrode was biased at 0.205 V with respect to the reference electrode (Ag/AgCl), and the resulting chronoamperometry signal was recorded as shown in Figure 1(c). The values obtained helped identify the current-producing capacity of each mutant. Among them, the highest peak current was given by mtr A+ (20 μA), and IV – 261 gave a low peak current (2 μA) within 3 minutes, validating the difference in the genetic make-up and EET capabilities. Technical and biological replicates were also conducted for all the 5 strains. The average standard deviation for the technical and biological replicates (n=3, OD600=0.065) was 0.09 μA and 0.56 μA respectively. A similar current trend for the same set of strains was obtained by Ian et al., [1] using a traditional bioelectrochemical system, thus validating our platform’s functionality and integrity. This system allows for parallel screening of wild type and mutant variations of multiple electroactive bacteria as demonstrated. The high throughput feature enabled by this device can also find application to characterize mutants generated by directed evolution workflows. Additionally, mechanical and electrical multiplexing can further improve the electronic instrumentation and connections between the wells for parallel readout and will also minimize human intervention during the current measurements. Chronoamperometry measurements is an important technique to characterize EET. Thus, a low-cost system like ours will help do that in a shorter time frame with minimal bacterial inoculum and for a larger number of electroactive bacterial species. In conclusion, we aim to show that a 3D carbon felt platform is miniaturized, and can be scaled to understand and characterize EET from electroactive bacteria in a high throughput manner. References Ian J. Campbell, Joshua T. Atkinson, Matthew D. Carpenter, Dru Myerscough, Lin Su, Caroline M. Ajo-Franklin, and Jonathan J. Silberg Biochemistry 2022 61 (13), 1337-1350 Figure 1

Lithography-Free Metaplasmonic Sensors Developed by TWD/GLAD Technique

Nowadays, plasmonic sensors are the most widely used and commercialized label-free optical biosensors and have become a widespread tool for studying chemical/biochemical interactions. Label-free, real-time, and direct measurements are the major benefits of the plasmonic sensors, including high-throughput surface bio-functionalization strategies without amplification or pretreatment of the sample [1]. The working principle of plasmonic sensing has been extensively described and reviewed over the decades [2], however, the possibility to develop cheap, effective, and clinically-accepted biosensors has recently become available due to the development of nanotechnology. Briefly, these nanostructures can be localized or can be arranged on 2D arrays of plasmonic metasurfaces, and can be fabricated by single-layer metallic films and a combination of metallic and dielectric films. The most popular plasmonic metals are gold and silver due to their high conductivity and low dielectric losses. Generally, top-down nanofabrication methods based on laser/e-beam lithography have been used, including nanostencil lithography based on shadow-masked nano-pattering and nanoimprint lithography [3]. Although such technologies have a high potential to achieve scalable and cost-effective nanofabrication at the wafer scale, these processes maintain the following main challenge: a master nano-mold/pattern is required to transfer metasurfaces with an associated high cost. Therefore, other technologies are the subject of research that overcomes this limitation and still offer an outstanding quality of metallic films, such as TDW (thermal dewetting) and GLAD (glancing angle deposition) (Fig.1). These techniques do not require master nano-mold/patterns; consequently, they can achieve lithography-free large-scale plasmonic metasurfaces [4]. TDW and GLAD usually generate quasi-ordered plasmonic metasurfaces compared to conventional lithographic methods.In this paper, the experimental results of the optical sensing properties of the sensors developed by the utilization of the combination of these two technologies in a single system are presented. The TWD/GLAD magnetron sputtering system has been designed and manufactured based on the Kurt J. Lesker MAG-Torus magnetrons, supplied with DC/RF power sources and an ECR manipulator that enables deposition at various angles with maximal 20 rpm rotation speed and heating option up to 850oC. The system is controlled by the software that enables deposition of the samples with the same parameters which pave the way for fabrication of the sensors on the industrial scale. The optical-sensing system was built based on an ST-VIS-50 spectrometer (Ocean Optics) and Tungsten Halogen Source (360-2000 nm, 2800 K, Ocean Optics) and optical table from Thorlabs. The obtained reflectance measurement has shown that the utilization of the GLAD technique decreases the reflectance peak in comparison with samples deposited without GLAD (flat samples). At the same time, angles in the range of 82-86oC seem to be preferable for nanostructure fabrication.Additionally, the utilization of the TWD technique, i.e. deposition at lower temperatures in the range of 60-100oC (depending on the substrate) and then annealed at higher temperatures such as 250oC and 300oC in a vacuum and under argon flow in the deposition chamber led to increased normalized response. However, the experiments have shown that the optimal annealing time is between 30-45 min depending on the SPR multi-structure, for example for Ag (6nm), Ti (2nm), and Au (2nm) the 30min at 250oC seems to be the best set. For such compositions, the surface sensitivity (nm/nm) and bulk sensitivity (nm/RIU) are more or less the same - 0.9 and 300, respectively. The obtained results are very promising for developing cheap, rapid, and very effective biosensors for various applications. Therefore, the obtained results seem to be very interesting for the ECS conference audience, for example, the developed Ag/Ti/Au multi-structures can be applied in novel organ-on-a-chip platforms for LADMET (liberations, absorption, distribution, metabolism, excretion, and toxicology) analysis [5].Fig. 1. Schematic diagram representation of lithography free methods for developing quasi-ordered metamaterials from left to right: Thermal dewetting and glancing angle deposition. The insert shows the chiral plasmonic nanospirals fabrication by glanced angle deposition [4].

(Invited) Advances in Wide Bandgap Thermal Resonant Infrared Detectors

Exploring the surface of distant planets, notably Venus, requires robust technologies capable of withstanding extreme environmental conditions while providing valuable scientific insights. This paper delves into the advancements made in designing an instrument tailored for capturing infrared (IR) images in the harsh Venusian environment, where temperatures soar to 500°C. The presented IR detector harnesses the power of a sparse array of resonant-based micromechanical devices, strategically addressing the limitations of existing technologies that can only withstand extreme conditions for limited durations.At the core of this technology lies the utilization of high-temperature-tolerant InAlN/GaN as the primary resonating element. GaN's resilience and high temperature tolerance make it a crucial player in challenging space environments. Its wide bandgap and chemical stability are advantageous for enduring harsh conditions during space missions. In tandem with GaN's intrinsic properties, high-temperature-tolerant meta-absorbers strategically positioned on the surface of each pixel play a pivotal role in the functionality of the IR detector. These meta-absorbers exhibit a remarkable capacity to absorb incoming infrared (IR) radiation, promptly transforming it into heat. The resonant frequency of these devices exhibits a linear shift with temperature variations, and a high-temperature-tolerant read-out electronic adeptly senses this frequency shift, enabling the seamless transfer of imaging data. Extraction of IR source power occurs through the resonance frequency shift in the exposed GaN resonator, compared to a reference resonator. The reference resonator, lacking the IR-absorbing layer, establishes a baseline for minimal resonant shifts.The sparse array configuration strategically reduces imaging elements to optimize power consumption and cost-effectiveness. Inspired by techniques employed in medical imaging instruments, this approach allows the construction of images from a low-power 2D array, striking a balance between imaging capabilities and processing efficiency. This sparse array configuration serves a dual purpose, streamlining signal routing for integrated read-out electronics and simplifying the overall integration and packaging of the IR imaging instrument. Monolithic integration of the read-out electronic with the sensor platform on the same chip overcomes challenges related to electrical and mechanical stability at high temperatures.The resonant effect delivers a remarkable enhancement in the signal-to-noise ratio, surpassing existing thermal detector technologies by a factor of 70×. Furthermore, the strategic implementation of sparse arraying results in approximately a 4× reduction in power consumption, presenting an efficient and resilient solution for imaging in extreme environments. Diverging from traditional IR detectors limited in performance at high temperatures, these detectors rely on the temperature coefficient of elasticity (TCE), offering a wide dynamic range of operational temperatures.Finally, this paper includes recent results measured at 500°C, demonstrating the instrument's capability to operate effectively in Venus's challenging conditions. These advancements pave the way for future planetary exploration missions, promising a deeper understanding of Venus's geological and atmospheric processes.

Engineering Topological States in Nanographenes

Our research focuses on the rational design, deterministic assembly, and detailed investigation of the physical phenomena emerging from quantum confinement effects in graphene nanomaterials. We pursue a highly integrated multidisciplinary program, founded on synthetic bottom-up approaches toward functional materials with precisely defined structure. We control their assembly into hierarchically ordered architectures and evaluate inherent physical properties using modern scanning probe techniques cross multiple length, time, and energy scales. We recently demonstrated the rational design and experimental realization of a graphene nanoribbon (GNR) superlattices that hosts a 1D array of symmetry-protected topological states, thus generating otherwise inaccessible electronic structure.1 This new class of materials can be thought of as an extended form of poly-acetylene wherein highly localized half-filled topological states replace the familiar single occupied p-orbitals along a conjugated π-system. Experimental results and first-principles calculations reveal that the frontier band structure of these GNR superlattices is defined purely by the coupling between adjacent topological interface states and can be tuned all the way from a semiconductor and a metal.2,3 This novel manifestation of 1D topological phases presents an entirely new route to band engineering in 1D materials based on precise control of their electronic topology and is a promising new platform for future studies of 1D quantum spin physics and metallicity in low dimensional carbon nanomaterials. 1. Topological Band Engineering of Graphene Nanoribbons. Rizzo, D. J.; Veber, G.; Cao, T.; Bronner, C.; Chen, T.; Zhao, F.; Rodriguez, H.; Louie, S. G.; Crommie, M. F.; Fischer, F. R. Nature 2018, 560, 204-206. 2. Inducing Metallicity in Graphene Nanoribbons via Zero-Mode Superlattices. Rizzo, D. J.; Veber, G.; Jiang, J.; McCurdy, R.; Cao, T.; Bronner, C.; Chen, T.; Louie, S. G.; Fischer, F. R.; Crommie, M. F. Science 2020, 369, 1597-1603. 3. Robust Metallic Zero-Mode States in Olympicene Graphene Nanoribbons. McCurdy, R. D.; Delgado, A.; Jiang, J.; Zhu, J.; Wen, E. C. H.; Blackwell, R. E.; Veber, G. C.; Wang, S.; Louie, S. G.; Fischer, F. R. J. Am. Chem. Soc. 2023, 145, 15162-15170.

Comparison of Gamma Analysis using Two Different Commercially available 2D Array Detectors for Pre-treatment Verification of Volumetric Modulated Arc Therapy

Comparison of Gamma Analysis using Two Different Commercially available 2D Array Detectors for Pre-treatment Verification of Volumetric Modulated Arc Therapy

Controlling cantilevered adaptive X-ray mirrors.

Modeling the behavior of a prototype cantilevered X-ray adaptive mirror (held from one end) demonstrates its potential for use on high-performance X-ray beamlines. Similar adaptive mirrors are used on X-ray beamlines to compensate optical aberrations, control wavefronts and tune mirror focal distances at will. Controlled by 1D arrays of piezoceramic actuators, these glancing-incidence mirrors can provide nanometre-scale surface shape adjustment capabilities. However, significant engineering challenges remain for mounting them with low distortion and low environmental sensitivity. Finite-element analysis is used to predict the micron-scale full actuation surface shape from each channel and then linear modeling is applied to investigate the mirrors' ability to reach target profiles. Using either uniform or arbitrary spatial weighting, actuator voltages are optimized using a Moore-Penrose matrix inverse, or pseudoinverse, revealing a spatial dependence on the shape fitting with increasing fidelity farther from the mount.

High Sensitivity and High Throughput Magnetic Flow CMOS Cytometers with 2D Oscillator Array and Inter-Sensor Spectrogram Cross-correlation.

In the paper, we present an integrated flow cytometer with a 2D array of magnetic sensors based on dual-frequency oscillators in a 65-nm CMOS process, with the chip packaged with microfluidic controls. The sensor architecture and the presented array signal processing allows uninhibited flow of the sample for high throughput without the need for hydrodynamic focusing to a single sensor. To overcome the challenge of sensitivity and specificity that comes as a trade off with high throughout, we perform two levels of signal processing. First, utilizing the fact that a magnetically tagged cell is expected to excite sequentially an array of sensors in a time-delayed fashion, we perform inter-site cross-correlation of the sensor spectrograms that allows us to suppress the probability of false detection drastically, allowing theoretical sensitivity reaching towards sub-ppM levels that is needed for rare cell or circulating tumor cell detection. In addition, we implement two distinct methods to suppress correlated low frequency drifts of singular sensors-one with an on-chip sensor reference and one that utilizes the frequency dependence of the susceptibility of super-paramagnetic magnetic beads that we deploy as tags. We demonstrate these techniques on a 7×7 sensor array in 65 nm CMOS technology packaged with microfluidics with magnetically tagged dielectric particles and cultu lymphoma cancer cells.