The limitation of hot spot cooling in microchips represents an important hurdle for the electronics industry to overcome with coolers yet exceed efficiencies required. Nanotechnology‐enabled heat sinks that can be magnetophoretically formed onto spots within a microfluidic environment are presented. CrO 2 nanoparticles, which dynamically chained and docked spots, establish tuneable high‐aspect‐ratio nanofins exchange between these liquid coolant. These also grown released on demand,...

The increasing demand for multifunctional polymer nanocomposites calls new technologies to simultaneously enhance mechanical, electrical, and thermal properties. This paper presents the use of an alternating-current electric field align graphene nanoplatelets (GnPs) in epoxy polymer. Theoretical modeling alignment process has identified key parameters that control rotation chain-formation GnPs. Experimental results reveal resulting exhibit anisotropic properties with significantly improved...

The conventional resonant-type microwave microfluidic sensors made of planar resonators suffer from limited sensitivities. This is due to the existence several distributed capacitors in their structure, where just one them acts as a sensing element. article proposes very high-sensitivity sensor microstrip transmission line loaded with shunt-connected series LC resonator. A large sensitivity for dielectric loadings achieved by incorporating capacitor resonator structure. Applying sample...

This paper presents a microwave sensor using pair of split-ring resonators (SRRs). The is designed by loading microstrip transmission line two identical SRRs on its sides. Differential permittivity sensing performed the with dielectric samples. One notch observed for loads, whereas non-identical samples produce split notches. sensor's operating principle described through circuit model analysis. A prototype fabricated and experimentally validated verifying differential concept. developed...

Strain sensors with high elastic limit and sensitivity are required to meet the rising demand for wearable electronics. Here, we present fabrication of highly sensitive strain based on nanocomposites consisting graphene aerogel (GA) polydimethylsiloxane (PDMS), primary focus being tune by tailoring cellular microstructure through controlling manufacturing processes. The resultant nanocomposite exhibit a gauge factor up approximately 61.3. Of significant importance is that can be readily...

This article presents the design of a 2-bit dual-band switchable terahertz absorber using stacked combination graphene and vanadium dioxide (VO

There is an increasing demand for high performance composites with enhanced mechanical and electrical properties. Carbon nanofibres offer a promising solution but their effectiveness has been limited by difficulty in achieving directional alignment. Here we report the use of alternating current (AC) electric field to align carbon epoxy. During cure process epoxy resin, (CNFs) are observed rotate applied field, forming chain-like structure. The fracture energies resultant nanocomposites...

The continued miniaturization of electronic components demands integrated liquid cooling systems with minimized external connections and fabrication costs that can be implanted very close to localized hot spots. This might challenging for existing because most them rely on pumps, connecting tubes, microfabricated heat sinks. Here, we demonstrate an system by utilizing a small droplet metal Galinstan, which is placed over the spot. Energizing square wave signal creates surface tension...

This letter presents a differential microwave permittivity sensor based on the reflection coefficient of microstrip lines terminated with series LC resonators. A 50 Ω resistor is considered in resonator. At resonance, transmission line experiences matched load causing zero. Two identical sensing elements are used for sensing, providing possibility simultaneous two samples detection. prototype fabricated and measured around 2 GHz validation principle.

Novel magnetite-carbon nanofiber hybrids (denoted by "Fe3O4@CNFs") have been developed coating carbon nanofibers (CNFs) with magnetite nanoparticles in order to align CNFs epoxy using a relatively weak magnetic field. Experimental results shown that field (∼50 mT) can these newly-developed form chain-like structure the resin. Upon curing, nanocomposites containing aligned Fe3O4@CNFs show (i) greatly improved electrical conductivity alignment direction and (ii) significantly higher fracture...

A microfluidic sensor based on a microstrip line loaded with composite resonator is reported in this paper. The combines shunt connected step impedance (SIR) and complementary split ring CSRR) etched the ground plane. By etching CSRR beneath patch of SIR, CSRR-loaded SIR exhibits two transmission zeros pole between. operating principle variation coefficient at frequency bare resonator, when material or liquid under test (LUT) contact (the sensitive element). designing closely spaced zeros,...

This paper presents a highly sensitive phase-variation sensor for dielectric constant measurements based on capacitively-loaded periodic slow-wave transmission line. Such line is implemented in microstrip technology, and the loading capacitors are formed by closely spaced rectangular patches. The sensing area of device delimited region occupied capacitive patches, where material under test (MUT) must be located. presence MUT modifies coupling capacitance between adjacent thereby producing...

Reconfigurable and tunable frequency selective surfaces (FSSs) are of significant interest in applications such as radomes adaptive screening unwanted wireless transmissions. Conventional FSSs require additional bias circuitry to tune the operating or change its characteristics. In this letter, a new tuning technique using spring resonator element is proposed. This can be applied FSS design make it reconfigurable and/or fine-tune response. The response adjusted by changing height <formula...

A new type of Frequency Selective Surface (FSS) with miniaturized resonator element is proposed. The FSS structure shown to have a unit cell dimension that 0.067 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> . Miniaturization the achieved by coupling two meandered wire resonators separated single thin substrate layer. capacitance due small separation between elements results in lowering resonant frequency. To demonstrate validity...

Due to the growing implications of energy costs and carbon footprints, need adopt inexpensive, green harvesting strategies are paramount importance for long-term conservation environment global economy. To address this, feasibility low power density ambient RF simultaneously from multiple sources is examined. A high efficiency multi-resonant rectifier proposed, which operates at two frequency bands (478-496 852-869 MHz) exhibits favorable impedance matching over a broad input range (-40 -10...

This paper presents a microwave sensor for simultaneous measurement of permittivity and thickness in dielectric materials. The is made dual-mode magnetic-LC resonator coupled to microstrip transmission line. Due resonance the resonator, response shows two zero frequencies. By applying materials various permittivities thicknesses both frequencies are modified. alterations used characterize samples under test. A prototype fabricated measured verifying proposed sensing principle.

A differential microwave permittivity sensor and comparator is designed using a microstrip transmission line loaded with magnetic-LC resonator. The aligned the electric wall of shows single zero, when it unloaded or symmetrically on both halves. second notch appears in response by asymmetrical dielectric loading two halves device. frequency splitting used to characterize properties samples under test. sensitivity enhanced removing mutual coupling between resonator metallic wall. sensors'...

This article presents a sensor based on branch line couplers for detection of dielectric samples. The two <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50~\Omega$</tex-math> </inline-formula> branches the coupler are used as sensing elements, where one them is considered reference and other test branch. Loading material under (MUT) modifies its electrical length characteristic impedance. breaks symmetry...

A phase variation-based rotation sensor is presented in this article. The realized using a coplanar waveguide (CPW) terminated with stepped impedance <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit {LC}$ </tex-math></inline-formula> resonator. circular dielectric slab rotating above the Rotation of modifies overall capacitance and, thus, input This, turn, reflection coefficient, which translated to...