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In this article, a new approach to detect the defective vias in substrate-integrated waveguide (SIW) structures is proposed. First, very near-field radiations of SIW structures are measured using either a single magnetic field probe or a fast electronically switched probe array. A source reconstruction method is utilized to calculate the equivalent electric and magnetic currents on the surface of the SIW structure under investigation. Thereafter, these equivalent sources are used to obtain the magnetic fields very close to the sample boards. A machine learning algorithm is used to distinguish the radiations that are due to the defective vias from those because of radiating parts of the circuit such as feed lines. The simulation and measurement results confirm the validity and accuracy of this high-resolution method.

This paper presents a flexible multi-shanks omini-directional neural probe array. The flexible probe includes eight shanks with different length, each shank contains 128 recording sites. Traditional Multilayer lithography is applied to fabricate the probe and a novel stacked structure is design with four-sided electrodes (32 sites on surface and 96 sites on sidewall) is proposed in this multi-shank array, which increases the electrode density of integration and the stacked structure can be readily scaled up to 1024 channels. It has been proved that the impedance at 1 kHz of the electrodes on the surface and the sidewalls are 830 kΩ and 1.1 MΩ in vitro respectively. With such design, longer life span can be achieved and the probe can capture richer neural signal. In addition, a method of microwire assisted implantation is proposed to ensure successful implantation in agar model.

We have developed a microelectromechanical system (MEMS)-based multiprobe scanning probe microscope (SPM) to improve imaging efficiency. The SPM head contains seven identical MEMS probes, and each of them integrates a displacement sensor and a Z-axis actuator. Force constant mode is designed based on the force feedback strategy rather than on the position feedback strategy for this kind of SPM head. A nano-measuring machine is equipped with the lateral XY scanners, which can reach a motion range of 25 mm × 25 mm. After calibration, the measurement of one-dimensional grating has been made to demonstrate the capability of multiprobe scanning.

A Parylene C polymer neural probe array with 64 electrodes purposefully positioned across 8 individual shanks to anatomically match specific regions of the hippocampus was designed, fabricated, characterized, and implemented in vivo for enabling recording in deep brain regions in freely moving rats. Thin film polymer arrays were fabricated using surface micromachining techniques and mechanically braced to prevent buckling during surgical implantation. Importantly, the mechanical bracing technique developed in this work involves a novel biodegradable polymer brace that temporarily reduces shank length and consequently, increases its stiffness during implantation, therefore enabling access to deeper brain regions while preserving a low original cross-sectional area of the shanks. The resulting mechanical properties of braced shanks were evaluated at the benchtop. Arrays were then implemented in vivo in freely moving rats, achieving both acute and chronic recordings from the pyramidal cells in the cornu ammonis (CA) 1 and CA3 regions of the hippocampus which are responsible for memory encoding. This work demonstrated the potential for minimally invasive polymer-based neural probe arrays for multi-region recording in deep brain structures. [2020-0018]

In the Attentional Boost Effect (ABE), images or words encoded with unrelated to-be-responded targets are later remembered better than images or words encoded with to-be-ignored distractors. In the realm of short-term memory, the ABE has been previously shown to enhance the short-term recognition of single-feature stimuli. The present study replicated this finding and extended it to a condition requiring the encoding and retention of colour-shape associations. Across four experiments, participants studied arrays of four coloured squares (the colour-only condition), four gray shapes (the shape-only condition) or four coloured shapes (the binding condition), paired with either a target letter (to which participants had to respond by pressing the spacebar) or a distractor letter (for which no response was required). After a short delay, they were presented with a probe array and asked to decide whether it matched or not the encoded array. Results showed that, in all conditions, the recognition of target-paired arrays was significantly better than the recognition of distractor-paired arrays. These findings suggest that the ABE can enhance feature binding.

Here we demonstrate high-throughput gigapixel confocal imaging using a massively parallel optical probe array with single directional infinite scanning. For implementation of the single directional infinite scan with high lateral resolution, a parallelogram array micro-objective lens module, composed of two wafer-level microlens arrays, is proposed to generate a massively parallel optical probe array for integration into the confocal imaging system, including an objective-side telecentric relay lens with a low-magnification. To test the feasibility of the proposed system with single directional infinite scanning, we designed and constructed a confocal imaging system using a parallelogram array of multi-optical probes with a massively parallel array size of 200 × 140. The constructed system provides a full width-half maximum lateral resolution of 1.55 μm, as measured by the knife-edge detection method, and a field-of-view width of 28.0 mm with a sampling interval of 1 μm/pixel.

The measuring instruments have some errors in the measurement of high water cut production wells, and many domestic oil fields are also in high water cut state. The measured data from the conventional production logging instrument are all almost inaccurate. This project has designed a staggered probe array flow meter well logging apparatus based on the characteristic of electromagnetic wave specific retention meter that can fully cover the wellbore fluid and improve flow measurement accuracy. According to the application in horizontal wells, the accuracy of this measuring instrument now has been proved to be more than 90% and can meet the requirements of production logging interpretation in horizontal wells.

We present an LED-waveguide-based neural probe array with the highest total light power delivery from a single commercial LED. A separable configuration between the LED and the waveguide has been proposed and verified experimentally for a disposable probe tip. The system comprises of a disposable MEMS optrode array and a reusable unit. The optrode array consists of a 4 × 4 array of 6 mm-long optical fibers assembled with thermally reflowed square-shaped glass microlenses. The reusable unit includes a domed top LED and driving circuitry. Measured light delivery efficiency of the optrode array and the total power efficiency of the probe were −10.6 dB and −21.6 dB, respectively.

Nanofiber scaffolds are widely used as the platform for three-dimensional culture of hepatocytes in vitro. The pore size of scaffolds plays an important role in promoting the infiltration and proliferation of hepatocyte. We show that the average pore size of electrospun scaffold increases from ~ 7.6 to 13.2 μm, while the average fiber diameter decreases from ~ 2.0 to 1.5 μm when collected by probe array collectors. Though increase in pore size decreases the tensile stress of scaffolds, it leads to enhance the proliferation and attachment of hepatocytes. Specifically, a 6 × 6 array scaffold which was prepared by probe collector was orderly arrayed. Compared with the conventional scaffold, the pore size of the arrayed scaffold doubled and the hydrophilicity was improved. When HepG2 cells were seeded on the arrayed scaffold, cells showed superior adhesion ability, better cell morphology and three-dimensional growth. These results indicated that the ordered 6 × 6 array scaffold has the potential as a suitable substratum for in vitro culture of hepatocytes.

In this paper, a new approach to enhance the speed and accuracy of the antenna near-field measurements and near-field to far-field (NF-FF) transformation is proposed. First, a uniform measurement is performed using an electronically switched probe array. Then an adaptive algorithm is developed that starts with a small number of samples and gradually focuses on the areas with highly dynamic near-field pattern and increases the number of samples over such regions. Thus, the number of required samples for an accurate result decreases significantly, and consequently the speed of the back projection algorithm increases.

In the context of the new international standard IEC 62209-3 developed within IEC Technical Committee TC 106, EURAMET is running European research project Vector SAR with the aim to provide the validation methods, software tools and datasets required for traceable calibration and uncertainty analysis of vector probe array systems that automatically determine the 3D electromagnetic field and Specific Absorption Rate (SAR) mapping using amplitude and phase information through a 3D reconstruction algorithm.

In this article, we propose a bidirectional peripheral nerve interface capable of long-term implantation for peripheral nerve motor signal acquisition and sensory signal feedback. We designed and manufactured a new concept of SPAE (Spiral Probe Array Electrode) electrode that can overcome the conflicting limitations of invasiveness and selectivity, and a high porosity sieve-type electrode that can induce natural nerve regeneration through maximizing porosity. Sieve-type electrodes and SPAE feasibilities were verified for neural signal acquisition. Based on this, we confirmed the possibility of using the high porosity sieve-type electrode and the new concept SPAE as peripheral nerve interfaces.

The exploitation of the mainland oilfield has entered a middle-late stage with high water-cut currently, and oil–gas–water multiphase flow exists commonly in exploitation of oilfield, accurate measurement of gas content has become a complex problem for the actual demand of dynamic monitoring in oil and gas field exploitation. In order to solve the problem of gas holdup measurement of the oil-gas-water multiphase flow in the oil-producing wells, this paper first constructed the mechanism model of a fiber-optic probe (FOP) for gas holdup measurement, and theoretically analyzed the feasibility of FOP to measure the gas holdup; simultaneously, the distribution characteristics of gas holdup for the upward oil-gas-water multiphase flow in a vertical pipe were simulated and analyzed by the FLUENT software; then the response characteristics of FOP piercing a gas bubble at different positions and different angles were analyzed. Secondly, the optimal structure of the fiber-optic probe array (FOPA) was optimized by analyzing the performance indexes of the ability to capture the cross-section gas holdup and the effect on the fluid flow interference. Finally, we designed and developed a FOPA-based logging instrument which could be applied to the complex environment of the oil-producing wells with high temperature, high pressure and narrow space. By the dynamic experiments carried out on the experimental facility of oil-gas-water multiphase flow and the onsite experiments carried out in Daqing Oilfield, the feasibility for the FOPA-based logging instrument to measure gas holdup was analyzed and verified.

Neural microprobes represent an important component of neural prosthetic systems where implanted microprobes record the electro-potentials generated by specific thoughts in the brain and convey the signals to algorithms trained to interpret these thoughts. Here, we present novel elongated multi-site neural probe that can reach depths greater than 10mm. We hypothesize that reaching such depth allows the recording of cognitive signals required to drive cognitive prosthetics. The impedance of the recording sites on the probes was on the order of 500 kΩ at 1 kHz, which is consistent with probes used for neurophysiological recordings. The probes were made porous using Xenon Difluoride (XeF2) dry etching to improve the biocompatibility and their adherence to the surrounding neural tissue. Numerical studies were performed to determine the reliability of the porous probes. We implanted the elongated probe in rats and show that the elongated probes are capable of simultaneously recording both spikes and local field potentials (LFPs) from various recording sites.

In this work, a novel hermetic packaging method using titanium and ceramic casing is proposed for long term implantable medical device. The proposed titanium-ceramic casing for implants has a better radio frequency (RF) transparency advantage as comparison to metallic materials. The proposed hermetic packaging method is used to integrate a high channels neural probe array and an active circuit module through a high density flexible cable without feedthrough integration. Hence, the profile of the integrated device achieved is as low as three millimeter and it is placed in the subdermal space. To evaluate the hermeticity of the device packaging, a helium gas leakage test was conducted and discussed. In vitro cytotoxicity test was also performed and evaluated.

We report the first Parylene C neural probe array that is anatomically matched to multiple regions of the hippocampus and successfully demonstrate recordings from targeted regions. No prior polymer probe array has achieved recordings at the depth of the hippocampus (5.5 mm probe length) and at such a high electrode density (64 electrodes). In addition, bare probes were implanted without the use of any insertion shuttles thereby enabling, for the first time, acquisition of dense neural information from deep brain targets of interest while restricting acute tissue disruption to the as-fabricated probe cross-section. Here, we present design and fabrication of the Parylene neural array, its electrical packaging scheme, and acute, in vivo recordings from pyramidal cells of both the cornu ammonis (CA) 1 and CA3 regions, essential players in the one-way hippocampal circuit that encodes memory.

Ultrasonic Systemsare useful for inspecting ceramic materials because ultrasonic waves are easily propagated insuch materials. Conventional ultrasonic testing (UT) methods cannot easily identify internal defects. This study built a visualization system for detecting and reconstructing internal defect images using probe array UT. Internal defect images were reconstructed by applying truncated singular value decomposition. We investigated how the sampling frequency and truncation index affect the reconstructed defect images.

The neural probe array is an important tool for getting the neural signals. Giving consideration to the biological compatibility and the demand of integrating in circuit, new fabrication process of a silicon-based three-dimension neural probe array was reported. The idea about milling in mechanical process and the method of structure for transfer were introduced in the fabrication. The 10*10 scale silicon-based three-dimension probe arrays integrated in the readout circuit directly were fabricated by means of flip chip and multi-blade mixing dicing techniques. In the entire fabrication process, no any high-temperature process and silicon wet etching process, which would damage the circuit, were included. Using the fabrication process above, the 10*10 scale silicon-based probe arrays with centre-to-centre separation of 400 μm were achieved. In the probe arrays, whose good rate was more than 95%, the width of a single probe was 100 μm, the tip angle was 25o, and the height was more than 1.4 mm. Through the fabrication process, it was not only reducing the pin count greatly, but also simplifying the interface effectively. By the in vivo experiment of the Sprague Dawley rat, the corresponding nerve signal was obtained.

Patients with paralysis, spinal cord injury, or amputated limbs could benefit from using brain&ndash, machine interface technology for communication and neurorehabilitation. In this study, a 32-channel three-dimensional (3D) multielectrode probe array was developed for the neural interface system of a brain&ndash, machine interface to monitor neural activity. A novel microassembly technique involving lead transfer was used to prevent misalignment in the bonding plane during the orthogonal assembly of the 3D multielectrode probe array. Standard microassembly and biopackaging processes were utilized to implement the proposed lead transfer technique. The maximum profile of the integrated 3D neural device was set to 0.50 mm above the pia mater to reduce trauma to brain cells. Benchtop tests characterized the electrical impedance of the neural device. A characterization test revealed that the impedance of the 3D multielectrode probe array was on average approximately 0.55 M&Omega, at a frequency of 1 KHz. Moreover, in vitro cytotoxicity tests verified the biocompatibility of the device. Subsequently, 3D multielectrode probe arrays were implanted in rats and exhibited the capability to record local field potentials and spike signals.

Neural probe array is utilized in neural recording, in the aim to understand the neural activity. Silicon is the common substrate used in neural probe array. However, due to the rigid nature, the silicon-based neural probe array causes cell damage during implantation into the brain tissue. This would reduce the signal-to-noise ratio. Therefore, flexible polymer probe is more suitable as it can help to minimize the tissue damage and thus increasing the signal-to-noise ratio. The lack of stiffness for the flexible probe is solved by coating it with polyethylene glycol (PEG). It stiffens the probe and can be dissolved in water, which allows the polymer probe to regain its flexibility. The proposed integrated probe with reduced distance between probe and ASIC will further help to improve the signal-to-noise ratio during neural recording. The coated flexible probe regained original impedance of 14.1 kΩ at a frequency of 1 kHz. A bench-top neural recording with the flexible probe array in saline solution will also be acquired.

Three dimensional (3D) single cell manipulation plays a critical role in the development of cell engineering. Cell manipulation techniques are potentially applied to reconstruct in vitro modeled cells. Our aim is to develop a dielectrophoretic (DEP) probe array for parallel 3D manipulation of single cells. This paper reports fabrication and evaluation of DEP probe array. We fabricated the 3D probe array with electrical connection to the tips. Single cells were collected from a 3D space and trapped on the probe tips. The cells were released from the tips in a parallel manner.

We present the first 3D multi-functional neural probe array integrated with optical, chemical, and electrical stimulation capabilities, developed for mapping the 3D functional connectivities among neurons cultured in a 3D hydrogel neuron chip. The proposed device is not only capable of stimulating neurons with various modalities but also tracking the propagated neural activities in the whole 3D hydrogel chip using the 3D electrode array. Using our 3D multi-functional neural probe array, we demonstrated successful in vitro experiments by electrically and chemically modulating neurons and recording neural signals on cultured neurons in the 3D hydrogel neuron chip.

Tactile sensation, which is one of the earliest developing sensory systems, is very important in the perception of an individual's body and the surrounding physical environment, especially in newborns. However, currently, only little is known about the response of a newborn's brain to tactile sensation. The objective of the present study was to determine the response of a newborn's brain to tactile sensation and to compare the brain responses to various sensory stimuli. Ten healthy newborns, 2-9 days after birth, were enrolled. A multichannel near-infrared spectroscopy system was used to measure brain responses. The probe array covered broad cortical areas, including the parietal, temporal, and occipital areas. We measured cortical hemodynamic changes in response to three different types of stimuli: tactile, auditory, and visual. Activated areas were analyzed by t-tests, and the number of activated channels among the three different stimuli was compared by χ²-tests. The results showed that when the brain responded to each type of stimulation, the corresponding primary sensory area was activated, and tactile stimuli induced broader areas of brain activation than the other two types of stimuli (auditory or visual). Thus, broad brain areas, including the temporal and parietal areas, were activated by tactile stimuli in early newborn periods. These results suggest that there are differences in newborns' reactions to various types of sensory stimuli, which may reflect the importance of tactile sensation in the early newborn period.

A method for chemically differentiating the surface of a set of small, closely-spaced, lithographically-defined Au features on a die, from another set of similar features intimately inter-dispersed, is described. The key enabler of the method is a standard electronics probe array adapted to carry out electrochemistry on the features. The probe array is used first to verify the electrical integrity of featuresandthequalityofelectricalcontactsbymeasuringelectricalresistance,then,inthepresenceoftheelectrolyte,simultaneously maintain one potential on one set of Au features and another potential on the other set in order to carry out desired electrochemical reactions. The technique was demonstrated on dies bearing 40 electrically isolated Au features (based on 5 μm wide stripes) accessed via 64 contact pads each 100×100 μm 2 in area. The array had 64 probes, of which 16 were maintained at a desorbing potential (-1.6 V vs. Ag/AgCl) and 48 at a stability potential (-0.3 V). The surface compositions were analyzed with time-of-flight secondary ion

Bio-signal probes providing stable observation with high quality signals are crucial for understanding how the brain works and how the neural signal transmits. Due to the weak and noisy characteristics of bio-signals, the connected interconnect length between the sensor and CMOS has significant impact on the bio-signal quality. In addition, long interconnections with wire bonding technique introduce noises and lead to bulky packaged systems. This letter presents an implantable through-silicon via (TSV) technology to connect sensors and CMOS devices located on the opposite sides of the chip for brain neural sensing applications. With the elimination of traditional wire bonding and packaging technologies, the quality of bio-signal can be greatly improved.

A probe array fabricated from a beryllium-copper metal sheet was developed in order to produce cost-effective microelectromechanical system (MEMS) probe cards. The probe array is fabricated via a simple, inexpensive process in which a heat current is used for annealing and a fusing current from a DC power supply is used for cutting the metal sheet. The stress relaxation time was 7 min during the application of a 4 A heat current, and the fusing current was 20 A. The contact force was approximately 1 gram force at a deflection of 100 μm, and the contact resistance from the tip of the probe to the end of the probe beam was 1.9 Ω. The probe array is suitable for use in probe cards, test sockets, and various types of manufacturing equipment.

An electron beam is detected by a 1D floating potential probe array in a relatively high density (1012–1013 cm−3) and low temperature (~5 eV) plasma of the Magnetic Reconnection Experiment. Clear perturbations in the floating potential profile by the electron beam are observed. Based on the floating potential profile and a current balance equation to the probe array tips, the effective width of the electron beam is determined, from which we determine the radial and toroidal beam current density profiles. After the profile of the electron beam is specified from the measured beam current, we demonstrate the consistency of the current balance equation and the location of the perturbation is also in agreement with field line mapping. No significant broadening of the electron beam is observed after the beam propagates for tens of centimeters through the high density plasma. These results prove that the field line mapping is, in principle, possible in high density plasmas.

Objective. The success of a cortical prosthetic device relies upon its ability to attain resolvable spikes from many neurons in particular neural networks over long periods of time. Traditionally, lifetimes of neural recordings are greatly limited by the body's immune response against the foreign implant which causes neuronal death and glial scarring. This immune reaction is posited to be exacerbated by micromotion between the implant, which is often rigid, and the surrounding, soft brain tissue, and attenuates the quality of recordings over time. Approach. In an attempt to minimize the foreign body response to a penetrating neural array that records from multiple brain regions, Parylene C, a flexible, biocompatible polymer was used as the substrate material for a functional, proof-of-concept neural array with a reduced elastic modulus. This probe array was designed and fabricated to have 64 electrodes positioned to match the anatomy of the rat hippocampus and allow for simultaneous recordings between two cell-body layers of interest. A dissolvable brace was used for deep-brain penetration of the flexible array. Main results. Arrays were electrochemically characterized at the benchtop, and a novel insertion technique that restricts acute insertion injury enabled accurate target placement of four, bare, flexible arrays to greater than 4 mm deep into the rat brain. Arrays were tested acutely and in vivo recordings taken intra-operatively reveal spikes in both targeted regions of the hippocampus with spike amplitudes and noise levels similar to those recorded with microwires. Histological staining of a sham array implanted for one month reveals limited astrocytic scarring and neuronal death around the implant. Significance. This work represents one of the first examples of a penetrating polymer probe array that records from individual neurons in structures that lie deep within the brain.

We assess the application of the second-generation Environmental Sample Processor (ESP) for the detection of harmful algal bloom (HAB) species in field and laboratory settings using two molecular probe techniques: a sandwich hybridization assay (SHA) and fluorescent in situ hybridization (FISH). During spring 2006, the first time this new instrument was deployed, the ESP successfully automated application of DNA probe arrays for various HAB species and other planktonic taxa, but non-specific background binding on the SHA probe array support made results interpretation problematic. Following 2006, the DNA array support membrane that we were using was replaced with a different membrane, and the SHA chemistry was adjusted. The sensitivity and dynamic range of these modifications were assessed using 96-well plate and ESP array SHA formats for several HAB species found commonly in Monterey Bay over a range of concentrations; responses were significantly correlated (p < 0.01). Modified arrays were deployed in 2007. Compared to 2006, probe arrays showed improved signal:noise, and remote detection of various HAB species was demonstrated. We confirmed that the ESP and affiliated assays can detect HAB populations at levels below those posing human health concerns, and results can be related to prevailing environmental conditions in near real-time.

A concept of an array actuator that is used to control the tip-sample separation of cantilevers in a two-dimensional (2D) probe array scanning system is proposed in this article. The feasibility of the concept is demonstrated with a 10 × 10 array actuator with 500 μm xy-pitches. The array actuator is made by slicing a bulk piezoceramic block. The obtained maximum actuation of a single probe was 2.19 μmp_p at ±168 Vp_p. A major issue for the actuator was the insufficient strength of the frame of the probe array chip. The demonstrated array actuator is highly compatible with previously developed parallel readout modules that use either a parallel optical beam or integrated piezoresistive deflection sensing. A large-scale 2D probe array is our ultimate target. © 2007 The Japan Society of Applied Physics.

A simultaneous measurement method using a parallel modulated probe array is proposed to measure the electromagnetic field radiated by antennas at different locations simultaneously. Each modulated probe is excited by a local signal with different frequency, so that the received intermediate frequency (IF) signal contains different frequency components which indicate the relative magnitude of the radio-frequency signal at positions of the probes, and all the IF components are measured simultaneously by a broadband microwave receiver. The effect of the local signal on the received IF signal and interaction effect between the probe array and the measured antenna are investigated. The accuracy of the method is shown by measuring the antenna radiation pattern. A 3D antenna radiation measurement system based on the present method is also developed. The performance of the system is demonstrated by measuring the radiation efficiency of antennas.