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When an elastomeric photomask is used for near-field contact printing, the high deformability of the elastomer mask plate enables gap-free full contact with the substrate, minimizing the effect of diffraction. This image-transfer technique provides sub-50 nm resolution and depth-of-focus-free lithographic capability with cost-efficient equipment. However, the method’s application is limited due to the lack of a wellestablished protocol for fabricating a nanoscale mask pattern on an elastomeric substrate, which remains a major technical challenge in the field of near-field contact printing. In this study, we present a reliable protocol for fabricating a metal-embedded polydimethylsiloxane (PDMS) photomask. Our fabrication protocol uses conventional nanofabrication processes to fabricate nanosized chromium mask patterns and then transfers the chromium patterns to an elastomeric mask plate using a sacrificial Ni layer. Our protocol provides a high flexibility mask pattern design, and highly stable metal patterns during transferring process. By careful optimizing the experimental parameters, we determined a perfect pattern transfer ratio, which avoided any mechanical failure of the metal pattern, such as debonding or wrinkling. We then fabricated a PDMS photomask and confirmed its nanoscale patterning resolution, with the smallest feature 51 nm in width under a 400-nm light source. We anticipate that our fabrication protocol will enable the application of cost-efficient and high-resolution near-field photolithography. (Received September 23, 2020; Accepted December 13, 2020)

Controlling ion transport in nanofluidics is fundamental to water purification, bio-sensing, energy storage, energy conversion, and numerous other applications. For any of these, it is essential to design nanofluidic channels that are stable in the liquid phase and enable specific ions to pass. A human neuron is one such system, where electrical signals are transmitted by cation transport for high-speed communication related to neuromorphic computing. Here, we present a concept of neuro-inspired energy harvesting that uses confined van der Waals crystal and demonstrate a method to maximise the ion diffusion flux to generate an electromotive force. The confined nanochannel is robust in liquids as in neuron cells, enabling steady-state ion diffusion for hundred of hours and exhibiting ion selectivity of 95.8%, energy conversion efficiency of 41.4%, and power density of 5.26 W/m2. This fundamental understanding and rational design strategy can enable previously unrealisable applications of passive-type large-scale power generation., Controlling ion transport in nanofluidics is fundamental to numerous material applications but designing a material for ion selection is challenging. Here the authors report a confined van der Waals graphene oxide membrane as cation selective channel for energy generation inspired by neuron electromotive force.

Photolithography is the prevalent microfabrication technology. It needs to meet resolution and yield demands at a cost that makes it economically viable. However, conventional far-field photolithography has reached the diffraction limit, which imposes complex optics and short-wavelength beam source to achieve high resolution at the expense of cost efficiency. Here, we present a cost-effective near-field optical printing approach that uses metal patterns embedded in a flexible elastomer photomask with mechanical robustness. This technique generates sub-diffraction patterns that are smaller than 1/10th of the wavelength of the incoming light. It can be integrated into existing hardware and standard mercury lamp, and used for a variety of surfaces, such as curved, rough and defect surfaces. This method offers a higher resolution than common light-based printing systems, while enabling parallel-writing. We anticipate that it will be widely used in academic and industrial productions., Photolithography is an established microfabrication technique but commonly uses costly shortwavelength light sources to achieve high resolution. Here the authors use metal patterns embedded in a flexible elastomer photomask with mechanical robustness for generation of subdiffraction patterns as a cost effective near-field optical printing approach.

Visualization of human senses has been of great interest for developing an emerging interactive display that can artificially stimulate synesthesia with numerous unprecedented applications. Especially, visualization of various daily sound and music, which are much more complicated than human touch, in a form of flexible thin film devices can be a great challenge. We present flexible artificial synesthesia electronics that visualize continuous and complicated sounds. The electronic device is made of a thin composite film of a piezoelectric polymer for sound generation and inorganic electroluminescence (EL) microparticles for direct visualization of input sound signals. Field-induced EL of the microparticles in the device depends upon the source sound wave, making their EL synchronized with sound arising from the piezoelectric actuation. The flexible artificial synesthesia devices with sound-synchronized EL (FASSEL) showed extreme mechanical tolerance that can be repeatedly folded and crumpled with visible sound, allowing a variety of unexplored applications including synchronous sound-lightings and wearable, on-body sound-vision systems to facilitate emotional interaction of human being with sound in a human-friendly form.

The quest for safe and high-performance Li ion batteries (LIBs) motivates intense efforts seeking a high-energy but reliable anode, cathode, and nonflammable electrolyte. For any of these, exploring new electrochemistry methods that enhance safety and performance by employing well-designed electrodes and electrolytes are required. Electrolyte wetting, governed by thermodynamics, is another critical issue in increasing Li ion transport through the separator. Herein, we report an approach to enhancing LIB performance by applying mechanical resonant vibration to increase electrolyte wettability on the separator. Wetting is activated at a resonant frequency with a capillary wave along the surface of the electrolyte, allowing the electrolyte to infiltrate into the porous separator by inertia force. This mechanical resonance, rather than electrochemistry, leads to the high specific capacity, rate capability, and cycling stability of LIBs. The concept of the mechanical approach is a promising yet simple strategy for the development of safer LIBs using liquid electrolytes.

Scanning probe microscopy techniques, such as atomic force microscopy and scanning tunnelling microscopy, are harnessed to image nanoscale structures with an exquisite resolution, which has been of significant value in a variety of areas of nanotechnology. These scanning probe techniques, however, are not generally suitable for high-throughput imaging, which has, from the outset, been a primary challenge. Traditional approaches to increasing the scalability have involved developing multiple probes for imaging, but complex probe design and electronics are required to carry out the detection method. Here, we report a probe-based imaging method that utilizes scalable cantilever-free elastomeric probe design and hierarchical measurement architecture, which readily reconstructs high-resolution and high-throughput topography images. In a single scan, we demonstrate imaging with a 100-tip array to obtain 100 images over a 1-mm2 area with 106 pixels in less than 10 min. The potential for large-scale tip integration and the advantage of a simple probe array suggest substantial promise for our approach to high-throughput imaging far beyond what is currently possible.

Development of a human-interactive display enabling the simultaneous sensing, visualisation, and memorisation of a magnetic field remains a challenge. Here we report a skin-patchable magneto-interactive electroluminescent display, which is capable of sensing, visualising, and storing magnetic field information, thereby enabling 3D motion tracking. A magnetic field-dependent conductive gate is employed in an alternating current electroluminescent display, which is used to produce non-volatile and rewritable magnetic field-dependent display. By constructing mechanically flexible arrays of magneto-interactive displays, a spin-patchable and pixelated platform is realised. The magnetic field varying along the z-axis enables the 3D motion tracking (monitoring and memorisation) on 2D pixelated display. This 3D motion tracking display is successfully used as a non-destructive surgery-path guiding, wherein a pathway for a surgical robotic arm with a magnetic probe is visualised and recorded on a display patched on the abdominal skin of a rat, thereby helping the robotic arm to find an optimal pathway., Designing human-interactive displays enabling the simultaneous sensing, visualization, and memorization of a magnetic field remains a challenge. Here, the authors present a skin-patchable magneto-interactive electroluminescent display by employing a magnetic field-dependent conductive gate, thereby enabling 3D motion tracking.

Dual-energy material decomposition (DEMD) is a well-established theoretical x-ray technique that uses low- and high-kilovoltage radiographs to separate soft tissue and bone in radiography and compu...

Background and objective Digital breast tomosynthesis (DBT) is a well-established multiplanar imaging modality in breast examinations designed to overcome the limitations of conventional mammography. However, reconstructed DBT images from the acquired projection data are often limited in image performance due mainly to blur artifacts resulting from inherent aspects of imaging systems, including detector resolution and the finite focal spot of the x-ray tube. Methods We investigated an effective blind-deblurring method based on a compressed-sensing scheme in an attempt to solve the blurring problem in DBT. We implemented the proposed algorithm and performed a systematic simulation and an experiment to demonstrate its viability. In both simulation and experiment, all of the projection data were taken with a tomographic angle of θ = 32° and an angle step of Δθ = 2°. The proposed deblurring algorithm was then applied to the projection data before performing the common filtered-backprojection-based DBT reconstruction process. Results The deblurred projection images showed much better image performance compared with the blurred projection images, demonstrating the viability of the proposed blind-deblurring scheme in conventional radiography. The PSNR and RMSE characteristics of the deblurred DBT image improved by factors of approximately 1.63 and 0.37, respectively, compared with those of the blurred DBT image. Conclusions Our results indicate that the proposed blind-deblurring method was effective in reducing the blurring problem in both DBT and in conventional radiography, excluding additional measurement of the system response function.

In conventional planar radiography, image visibility is often limited mainly due to the superimposition of the object structure under investigation and the artifacts caused by scattered x-rays and noise. Several methods, including computed tomography (CT) as a multiplanar imaging modality, air-gap and grid techniques for the reduction of scatters, phase-contrast imaging as another image-contrast modality, etc., have extensively been investigated in attempt to overcome these difficulties. However, those methods typically require higher x-ray doses or special equipment. In this work, as another approach, we propose a new model-based radiography restoration method based on simple scatter-degradation scheme where the intensity of scattered x-rays and the transmission function of a given object are estimated from a single x-ray image to restore the original degraded image. We implemented the proposed algorithm and performed an experiment to demonstrate its viability. Our results indicate that the degradation of image characteristics by scattered x-rays and noise was effectively recovered by using the proposed method, which improves the image visibility in radiography considerably.

We report the two-pulse time-resolved photocurrent measurements in a group VII ReS 2 . The absence of bias dependence on the photocurrent recovery implies that the escape time of photoexcited carrier is much faster than electron-hole recombination.

Fabrication strategies that pursue “simplicity” for the production process and “functionality” for a device, in general, are mutually exclusive. Therefore, strategies that are less expensive, less equipment-intensive, and consequently, more accessible to researchers for the realization of omnipresent electronics are required. Here, this study presents a conceptually different approach that utilizes the inartificial design of the surface roughness of paper to realize a capacitive pressure sensor with high performance compared with sensors produced using costly microfabrication processes. This study utilizes a writing activity with a pencil and paper, which enables the construction of a fundamental capacitor that can be used as a flexible capacitive pressure sensor with high pressure sensitivity and short response time and that it can be inexpensively fabricated over large areas. Furthermore, the paper-based pressure sensors are integrated into a fully functional 3D touch-pad device, which is a step toward the realization of omnipresent electronics.

Digital tomosynthesis (DTS) is a geometric tomography technique using a limited-angle scan. It has been popularly used in both medical and industrial x-ray imaging applications. DTS provides the tomographic benefits of computed tomography with reduced dose and time. However, conventional DTS reconstruction based on the computationally cheap filtered back-projection (FBP) method typically produces poor image quality due to limited angular samplings. To overcome these difficulties, iterative reconstruction methods are often used in DTS reconstruction as they have the potential to provide multiplanar images of higher quality than conventional FBP-based methods. However, they require enormous computational cost in the iterative process, which remains an obstacle to practical applications. In this study, we propose a method for effectively reducing limited-angle artifacts in conventional FBP reconstruction, using a state-of-the-art deep learning scheme with a convolutional neural network. Our results indicate that the proposed DTS reconstruction method effectively minimized limited-angle artifacts, thus improving image performance in DTS, and that further it provided good image quality in both sagittal and coronal views (as in computed tomography) as well as in axial view.

In article number 1802351, Cheolmin Park and co‐workers demonstrate an interactive skin display with epidermal stimuli electrode, allowing for the simultaneous sensing and display of multiple epidermal stimuli such as temperature, sweat and pressure on a single device. The device is directly mounted on human skin, which by itself serves as a field‐responsive floating electrode of the device.

Purpose To investigate safety and efficacy of hybrid treatment for infected aortic and iliac aneurysms. Materials and Methods Between July 2007 and May 2011, hybrid treatment was performed in 6 male patients (mean age, 67.7 y; range, 57–76 y). Hybrid treatment consisted of extraanatomic bypass (EAB) and isolation of infected aneurysm with vascular plugs. Aneurysms were divided into primary and secondary infected aneurysms. Primary infected aneurysm refers to an aneurysm arising from bacterial infection of the native arterial wall; secondary infected aneurysm refers to infection involving an aneurysm that was previously treated with graft placement. Results The infected aneurysm involved the infrarenal abdominal aorta in 4 patients and common iliac artery in 2 patients. Hybrid treatment was successful in all 6 patients. The 3 patients with primary infected aneurysms required only hybrid treatment, whereas infected graft excision and new graft interposition was performed in 2 of the 3 patients with secondary infected aneurysms. No 30-day mortality or complications were reported. During mean follow-up of 58.6 months (range, 32.6–75.8 months), 1 patient (17%) with a secondary infected aneurysm who did not undergo additional surgery died 32.6 months after hybrid treatment from hypovolemic shock secondary to recurrent aortoenteric fistula. Cumulative survival was 100%, 100%, 83%, and 83% at 3 months, 1 year, 3 years, and 5 years. Conclusions Hybrid treatment appears to be a stand-alone, curative treatment for primary infected aneurysms and serves as bridge therapy to subsequent surgery for secondary infected aneurysms.

Computed tomography (CT) images obtained at different monochromatic X-ray beam energies can be synthesized from conventional dual-energy CT scans. This approach to synthesizing monochromatic CT images is based on basis material decomposition and the knowledge of attenuation of basis materials. The main benefits of virtual monochromatic CT (VMCT) images include reduction of beam-hardening artifacts and provision of accurate atteuation measurements. Despite the VMCT's benefits, main concerns in the use of VMCT in clinics may be high radiation dose the patient is exposed to. In this study, we investigated a projection-based sparse-view VMCT method in an attempt to overcome these difficulties. We performed a computational simulation and evaluated the feasibility of using the VMCT method in sparse-view CT. Two polychromatic data sets of 90 projections, far less than what is required by the Nyquist sampling theory, were simulated at 80 kVp and 140 kVp and used to synthesize VMCT images at a monochromatic energy range of 40–140 keV . VMCT image characteristics were quantitatively evaluated in terms of intensity profile, the contrast-to-noise ratio, and the signal-to-noise ratio. Our results indicate that the CS-based algorithm produced high-quality sparse-view CT images, and thereby the proposed VMCT method yielded CT image results of improved beam-hardening artifacts and quantitative measurements.

This study investigated analytic digital tomosynthesis (DTS) reconstruction in partial sampling with a multislit collimator that partially blocks the x-ray beam to the patient during projection data acquisition, thereby reducing excessive radiation dose to patients. Partially-sampled DTS images reconstructed using the analytic filtered-backprojection (FBP) algorithm usually suffer from severe bright-band artifacts around multislit edges of the collimator due to incomplete spatial sampling. In this study, a new prior sinogram interpolation method was introduced to the analytic DTS reconstruction in partial sampling to alleviate such artifacts. To verify the proposed DTS method, we conducted a systematic simulation and investigated image characteristics. Three multislit collimator layouts of C(2/2), C(3/3), and C(4/4) with a 50% duty cycle were designed and used in the simulation. Here C(n/n) denotes a collimator layout that blocks the x-ray beam over n detector pixels vertically with a n-pixel interval. All projections were obtained at a tomographic angle of θ = ±40o and an angle step of Δθ = 2o and used to reconstruct DTS images using the FBP algorithm. Our results indicate that the proposed sinogram interpolation method effectively minimized bright-band artifacts in analytic DTS reconstruction in partial sampling, thus maintaining the image quality.

Silica aerogels were synthesized via solvent exchange/surface modification of wet gels from waterglass using IPA/TMCS/n-Hexane solution. The densities, porosities, and specific surface areas of the aerogel were in the range of 0.128–0.153 g/cm3, 93–95%, and 598–795 m2/g, respectively. Aerogel-PVB composites were manufactured by hot pressing. Aerogels were crushed and mixed with PVB. Three mixing methods were performed. The aerogel-PVB composites had densities of 0.19–1.09 g/cm3, and thermal conductivities of 0.03–0.12 W/(m · K). Density and thermal conductivity can be controlled by aerogel volume fraction and the mixing method. The modulus of rupture of aerogel-PVB composites was in the range of 0.15–46.5 MPa.

The fundamental challenge in designing transparent pressure sensors is the ideal combination of high optical transparency and high pressure sensitivity. Satisfying these competing demands is commonly achieved by a compromise between the transparency and usage of a patterned dielectric surface, which increases pressure sensitivity, but decreases transparency. Herein, a design strategy for fabricating high-transparency and high-sensitivity capacitive pressure sensors is proposed, which relies on the multiple states of nanoparticle dispersity resulting in enhanced surface roughness and light transmittance. We utilize two nanoparticle dispersion states on a surface: (i) homogeneous dispersion, where each nanoparticle (≈500 nm) with a size comparable to the visible light wavelength has low light scattering; and (ii) heterogeneous dispersion, where aggregated nanoparticles form a micrometer-sized feature, increasing pressure sensitivity. This approach is experimentally verified using a nanoparticle-dispersed polymer composite, which has high pressure sensitivity (1.0 kPa-1 ), and demonstrates excellent transparency (>95%). We demonstrate that the integration of nanoparticle-dispersed capacitor elements into an array readily yields a real-time pressure monitoring application and a fully functional touch device capable of acting as a pressure sensor-based input device, thereby opening up new avenues to establish processing techniques that are effective on the nanoscale yet applicable to macroscopic processing.

A new modified ambient drying process for synthesizing silica aerogels cost-effectively from waterglass has been developed. Crack-free silica aerogels were obtained via solvent exchange/surface modification of wet gels using IPA/TMCS/n-Hexane solution. Silica aerogels were heated at different temperatures. The effects of heating temperature on chemical bonding state of aerogels were investigated by means of DTA and FTIR. The surface characteristic of the aerogel was hydrophobic when heat-treated under 350°C. The porosities, densities, and specific surface areas of the silica aerogels were in the range of 93–94%, 0.12–0.15 g/cm3, and ∼630 m2/g, respectively. Distinct spring back phenomena were observed in surface modified wet gels during drying.

Color generation by thermochromic materials offers several advantages over the light-based technology: a passive circuit element-driven simplified device layout, cost-effectiveness, and clear visibility. However, thermochromic materials need to be effectively coupled with an external heat source to induce coloration, which generally involves slow heat transfer processes that are not suitable for potential display applications. Here, a method for molecular printing of a thermochromic ink with a low heat capacity, enabling an unprecedented, fast color switching without any optoelectronic elements, is demonstrated. Molecularly printed ink is patterned on fabricated microheaters that induce transient local heat generation, facilitating local heating and cooling processes. Depending on the density of the thermochromic ink, that is, the number of microcapsuled dyes in the form of a monolayer resulting in a low heat capacity, the chroma of the patterned ink could be increased. Using this technique, the thermochromic ink could be printed over centimeter scales, with cyan-magenta-yellow-black colors at a color-switching rate of 20–500 ms, to be integrated into the thermochromic device prototype for potential display applications.

The battery shape is a critical limiting factor affecting foreseeable energy storage applications. In particular, deformable metal–air battery systems can offer low cost, low flammability, and high capacity, but the fabrication of such metal–air batteries remains challenging. Here, it is shown that a shape-reconfigurable-material approach, in which the deformable components composed of micro- and nanoscale composites are assembled, is suitable for constructing polymorphic metal–air batteries. By employing an aluminum foil and an adhesive carbon composite placed on a cellulose scaffold as a substrate, an aluminum–air battery that can be deformed to an unprecedented high level, e.g., via expanding, folding, stacking, and crumpling, can be realized. This significant deformability results in a specific capacity of 128 mA h g−1 (496 mA h g−1 per cell; based on the mass of consumed aluminum) and a high output voltage (10.3 V) with 16 unit battery cells connected in series. The resulting battery can endure significant geometrical distortions such as 3D expanding and twisting, while the electrochemical performance is preserved. This work represents an advancement in deformable aluminum–air batteries using the shape-reconfigurable-material concept, thus establishing a paradigm for shape-reconfigurable batteries with exceptional mechanical functionalities.

A thermochromic-based interactive sensor that can generate local color switching and pressure mapping is developed using a 2D array of resistive pressure sensor switch. This thermochromic-based interactive sensor will enable the visualization of localized information in arbitrary shapes with dynamic responses in the context of serial/parallel pressure mapping and quantifying capability without optoelectronic arrays.