We report the design, fabrication, and experimental characterization of first fully 3D-printed, multi-material miniature magnetic actuators for compact systems in literature. The actuator design integrates a bonded hard magnet made NdFeB microparticles embedded Nylon 12 matrix (55% by volume) with structural support elements pure 12. device is 10 mm-diameter, 1.2 mm wall-thick, 9 tall cylindrical frame that mounts on an off-the-shelf solenoid diameter, 100 μm-thick, leak-tight membrane...

This article describes a versatile method to fabricate magnetic microstructures with complex two-dimensional geometric shapes using magnetically assembled iron oxide (Fe3O4) and cobalt ferrite (CoFe2O4) nanoparticles. Magnetic pole patterns are imprinted into magnetizable media, onto which nanoparticles from colloidal suspension defined via the shaped field gradients. The kinetics of this assembly process studied by evaluation microstructure features (e.g., line width height) as function...

The fabrication and integration of microactuators with 3D micromechanisms are necessary to develop microrobots higher capability complexity. In this work, a two-step method combining printing two-photon polymerization (TPP) aluminum sputtering is demonstrated. Actuators using two different transduction mechanisms (thermal electrostatic) were fabricated in process, thermal actuator was printed mechanism three-dimensional space without additional assembly steps. This work also provides...

Phosphors of Bi4Ge3O12:Eu3+ were obtained by using the polymeric precursor route. After confirming Eu incorporated into Bi4Ge3O12 lattice, we analyzed magnetic behavior in systems with 0%, 2%, 5%, and 10%. The magnetization vs field measurements evidenced ferromagnetism all samples, different saturation values. In pristine structure, is directly related to Bi vacancies, where neighbor O atoms induce spin polarization. ferromagnetic characteristics are enhanced 2% content because take on...

This work focuses on fabricating a photocatalyst nanocomposite based MnFe2O4@ZnO for degrading Red Amaranth azo dye. Manganese ferrite (MnFe2O4) magnetic nanoparticles were synthesized via hydrothermal method, while ZnO thin film, acting as the photoactive layer, was deposited cores using atomic layer deposition (ALD) technique. X-ray diffraction (XRD) confirmed spinel structure of MnFe2O4 and hexagonal wurtzite phase ZnO. The crystallite size, determined from (311) peak, 36.5 nm; this value...

A combination of TRIM and FLOODS models the effect radiation damage on AlGaN/GaN HEMTs. While excellent fits are obtained for threshold voltage shift, do not fully explain increased reliability observed experimentally. In short, addition negatively-charged traps in GaN buffer layer does significantly change electric field at gate edges fluence levels seen this study. We propose that negative trapped charge nitride/AlGaN interface actually produces virtual-gate results decreasing magnitude...

In this article, we demonstrate the application of diamagnetically levitated milli-robots for 2D micro-assembly 10-μm polymer microspheres and other silicon microfabricated parts. By using an optical microscope feedback (imaged at 27 Hz), are able to long-term open-loop stability (up 78 hr) sub-micron micro-robots. Furthermore, due low hysteresis high compliance in magnetic drive milli-robots, directly use conjunction with machine vision as a force sensor. Soft polymer-based end effectors...

The effects of high energy proton irradiation dose on dc performance as well critical voltage the drain-voltage step-stress AlGaN/GaN electron mobility transistors (HEMTs) were investigated to evaluate feasibility HEMTs for space applications, which need stand a variety irradiations. irradiated with protons at fixed 5 MeV and doses ranging from 109 2 × 1014 cm−2. For characteristics, there was only minimal degradation saturation drain current (IDSS), transconductance (gm), mobility, sheet...

This article presents a novel way to estimate magnetodielectric composites' complex permittivity ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\varepsilon $</tex-math> </inline-formula> ) and permeability notation="LaTeX">$\mu$</tex-math> ). A methodology based on artificial neural network (ANN) modeling is proposed determine from notation="LaTeX">$S$</tex-math> -parameter measurements around 2.45 GHz,...

This work presents the design, modeling, and fabrication of a whisker-like sensor capable measuring whisker's angular displacement as well applied moments at base whisker. The takes advantage readily accessible low-cost 3D magnetic sensors to transduce whisker deflections, planar serpentine spring structure is used provide mechanical suspension for rotate. prototype was characterized, calibrated, compared with analytical models system field. showed moment sensing range 1.1N·mm when deflected...

Goal: This paper investigates the practicality of using a small, permanent magnet to capture magnetic particles out high-viscosity biological fluids, such as synovial fluid. Methods: Numerical simulations are used predict trajectory toward magnet. The determine "collection volume" with time-dependent size and shape, which determines number that can be captured from fluid in given amount time. Results: viscosity strongly influences velocity magnet, hence, collection volume after In regards...

We demonstrate GaN-based thin light-emitting diodes (LEDs) on flexible polymer and paper substrates covered with chemical vapor deposited graphene as a transparent-conductive layer. Thin LEDs were fabricated by lifting the sapphire substrate off Excimer laser heating, followed transfer of to substrates. These coated tri-layer wet method. Optical electrical properties lift-offed characterized under both relaxed strained conditions. The remained conducting when graphene/paper structure was...

The behavior of spherical single-domain magnetic nanoparticles in strong inhomogeneous fields is investigated through Brownian dynamics simulations, taking into account dipole–dipole interactions, repulsive hard-core Yukawa potential, hydrodynamic particle-wall and the mechanism dipole rotation presence a field. capture process prototypical field gradients generated by sudden reversal perpendicular magnetization flat substrate (defining "capture line") studied as function strength volume...

This work demonstrates the first sputtered thin-film nickel-titanium (NiTi) shape-memory alloy (SMA) actuators combined with direct 3D printing of polymeric structures. Resulting are fast to prototype, reliable and stable (up 5000 cycles), can utilize complex geometries challenging achieve conventional MEMS microfabrication. The actuator design uses printed polymer as passive layer in unimorph actuators, adding significant versatility design. An designed for high force-displacement was...

Shape memory alloy (SMA) actuators can provide significant advantages for small-scale robotics given their robustness, energy density, and low voltage actuation. However, NiTi thin films typically found in SMA microactuators do not often useful forces displacements microrobotic applications. This work presents a fabrication process which film are integrated with two-photon polymerization (TPP) 3D printing to scale these up use mesoscale systems. Individual unimorph characterized respect...

In this work, we synthesized nanoparticles of the Ni1-xCoxFe2O4 (with x = 0.25, 0.50, and 0.75) inverse spinel by hydrothermal method. Scanning transmission electron microscopy (STEM) analysis elemental characterization revealed formation order ∼3 nm with a homogeneous distribution their constituents, denoting correct material synthesis. The results show that as content Co2+ increases, cell parameter structures increases crystallite size increases. Besides, magnetic exhibits an increase in...

Gift cards are an increasingly popular payment platform. Much like credit cards, gift rely on a magnetic stripe to encode account information. Unlike however, the EMV standard is entirely infeasible for due compatibility and cost. As such, much of fraud that has plagued started move towards resulting in billions dollars loss annually. In this paper, we present system detecting counterfeit does not require original card be measured at time manufacture. Our relies phenomenon known as jitter,...

Proton irradiation from the backside of samples were employed to enhance off-state drain breakdown voltage AlGaN/GaN high electron mobility transistors (HEMTs) grown on Si substrates. Via holes fabricated directly under active area HEMTs by etching through substrate for subsequent proton irradiation. By taking advantage steep drop at end energy loss profile, defects created sample could be precisely placed specific locations inside HEMT structure. There no degradation current nor enhancement...

This paper explores a method for incorporating samarium cobalt (both Sm <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Co xmlns:xlink="http://www.w3.org/1999/xlink">17</sub> and SmCo xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ) inclusions into screen-printed barium hexaferrite (BaFe xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">19</sub> films in order to tune the ferromagnetic...

AlGaN/GaN based metal–insulator–semiconductor high-electron-mobility transistors (HEMTs) using a plasma enhanced atomic layer deposited 10 nm AlN as the gate insulator and passivation were demonstrated. A refractive index of 1.92 for was measured an ellipsometer, which slightly lower than that bulk AlN. The deviation from ideal value caused by surface oxidation, this confirmed X-ray photoelectron spectroscopy Auger depth profiling analyses. HEMT drain current modulated with voltages ranging...

AlGaN/GaN HEMTs grown on both-side-polished sapphire substrates were successfully lifted-off with a 193-nm UV excimer laser system. The photon energy of the 193 nm is larger than band gap AlN and thus it can be used to lift-off AlGaN HEMT structures or interfacial layers prior growth GaN buffer layers. chip was warped showed 25–42% reduction saturation drain current. There no degradation observed either in forward reverse gate current-voltage (I-V) characteristics punch-through voltage....

This work demonstrates two strategies to reduce the energy required for actuation of thin film NiTi unimorph actuators with 3D printed polymeric passive layers. First, by taking advantage printing, a low mass and high stiffness layer can be used achieve faster heating/cooling rates. ultimately reduces time threshold temperature. The second approach uses higher currents shorter periods reach predefined operational temperature less energy. Using well-designed combined pulsed results in...

This work describes the simulation, batch fabrication, functional demonstration, and magnetic field/force characterization of highly miniaturized ∼3.8 mm3 axisymmetric electropermanent magnets (EPMs). Two different bonded high-coercivity, rare-earth permanent magnet powders (∼15 µm Sm2Co17 particles 6 NdFeB particles) were evaluated for fabrication fixed in EPM, reaching latching force on/off ratios 191:1 303:1 respectively. Compared to conventional side-by-side architecture, design...

<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Objective:</i> The objective of this study is to design a physical model magnetic filtration system which can separate nanoparticle (MNP)-tagged cytokines from fluid at physiologically relevant flow rates employed during cardiopulmonary bypass (CPB) procedures. xmlns:xlink="http://www.w3.org/1999/xlink">Methods:</i> Navier-Stokes equations for the pressure driven in chamber and quasistatic stray...