Based on the resonant electric field microsensors with coplanar electrodes, a novel non-intrusive measurement scheme of DC power-line voltage suitable for actual product is presented in this paper. Compared with using microsensors directly without some protection, employing the proposed scheme can avoid the influence of humidity and electromagnetic disturbance on non-contact voltage measurement. A

Droplet motion has been a long-standing interest in microfluidics as it is often limited by the high operating voltages, which hampers the development of consumer applications. Forces generated by liquid dielectrophoresis (L-DEP) can enhance surface wetting, without requiring chemical modification or surface texturing. This work presents a droplet actuating platform to control the wetting behaviour

This work investigates the design methodology to obtain large electromechanical coupling factor () and high quality factor (Q) of shear-horizontal surface acoustic wave (SH-SAW) resonators based on the thin-film lithium niobate-on-insulator (LNOI) technology. The guided SH wave can be excited through interdigital transducers and propagate at the very surface of the material stackings. Such a guided

We report on a piezoelectric micromachined ultrasonic transducer (PMUT) driven in a nonlinear regime, generating chaotic amplitude modulated ultrasonic waves. At large enough drives, the PMUT enters in the Duffing regime which opens a hysteresis with two available states. By modulating the frequency of the driving signal, the system may switch between both states, and selecting the appropriate modulation

In this work, a novel on-chip micro pressure sensor was developed for microfluidic pressure monitoring. Polydimethylsiloxane (PDMS) microfluidic chip contained a working fluid channel with a sealed detection channel beneath it. Any change in pressure in the working fluid channel would change the volume of the detection channel. A mixture of two immiscible fluids was sealed in the detection channel

Rapid detection of small amounts of Staphylococcus aureus (S. aureus) in whole blood and the corresponding diagnosis of S. aureus is a complicated and time-consuming process. Gold standard is to culture and grow bacteria before detection, which typically takes several days and requires skilled personnel. Here, we developed a microfluidic cartridge for the culture-free isolation of S. aureus in blood

Patterning using a focused ionizing radiation beam provides a high spatial resolution but is not feasible when creating large arrays of microstructures. We propose the optimization of x-ray lithography parameters to create submicropores in a low-sensitivity material (polyethylene terephthalate) using a wide x-ray beam. This optimization results in the fabrication of regularly arranged micropores with

Bottom-up grown single-crystalline silicon nanowires (SiNWs) are highly intriguing to build nanoscale probes, for instance for atomic force microscopy (AFM), due to their mechanical robustness and high aspect ratio geometry. Several strategies to build such nanowire-equipped probes were explored but their fabrication is still elaborate, time-consuming and relies partly on single-crystalline substrates

A novel microfluidic device for efficient passive mixing is reported. A series of sharp corner structures designed on side wall of an arc microchannel was utilized to induce three-dimensional vortices, which strongly stretched and folded the interface and significantly increased the interfacial contact area between different fluids. Additionally, the sharp corner structure induced high radial velocity

Arrays of pn junctions have been fabricated with n-Si microneedles. In situ doping vapor–liquid–solid (VLS) growth has been carried out with p-Si substrate having metallic catalyst (Au) dots on its surface, using Si2H6 and PH3 for supplying Si and phosphorus to fabricate n-Si microneedles on the surface of p-Si substrate in vertical direction; thus, pn junctions have been fabricated at microneedle-substrate

Stenosis reduces the effective lumen area in the tracheal and bronchial segments of the airway anatomy. Loss in patency due to obstruction increases resistance to airflow; thus, severe narrowing is often associated with morbidity and mortality. Etiologies such as congenital tracheal stenosis, tracheomalacia, laryngeal and subglottic stenosis, atresia are few among the many pathologies causing major

In this paper, optoelectronic characteristics and related switching behavior of one monolithically integrated silicon light-emitting device (LED) with an interesting wavelength range of 400–900 nm are studied. Through the comparison of two types of geometry, Si avalanche-based LED and Si field-effect LED (Si FE LED), in the same device, we establish the dimensional dependence of the switching speed

A mechanically reliable micrometric scale conductive wire fabrication method was developed using silver paste. In order to increase the bonding strength between silver particles, a method was developed for filling the space between particles with UV photopolymer. The UV photopolymer covers the top of a mold filled with silver paste, after which vacuum forces are generated by the evaporation of the

This work analyses circuit phase delay for carrier-modulation MEMS capacitive gyroscopes. The temperature-dependent circuit phase delay is a major source of gyroscope output drift, which deteriorates the gyroscope bias instability (BI) and angle random walk (ARW). Effects of both drive-mode and sense-mode circuit phase delay on gyroscope performance when using different signal extraction architectures

High frequency printed circuit board (PCB), as the significant support for 5G technology, has been receiving intense attention from the increasing number of scholars. Concerning precision fabrication of high frequency PCBs, micro hole drilling is deemed as one of the extremely crucial challenges. In this study, the coated drill bits’ wear and micro hole quality were investigated through the drilling

This paper reports on a rapid, lossless process for the bonding of poly(methyl methacrylate) (PMMA) substrates for use in microfluidic devices for blood tests, utilizing H2O plasma, and H2O linked rapid thermal annealing (RTA) treatments. The bonding of PMMA produced with H2O plasma linked with RTA was analyzed, and its effect on the bonding of free radicals was investigated. The PMMA surface treatment

This paper describes the investigation of a novel low-cost silicone-based hybrid vibration energy harvester (SHVEH) for converting machine vibrations into useful electrical power for wireless sensor nodes. Due to a novel fabrication technique, the harvester has the benefit of incorporating two transduction mechanisms (electromagnetic and piezoelectric) into a single silicone housing for improved output

Fused silica (FS) micro hemispherical resonators have attracted considerable interest for application in high-performance sensors. Manufacturing of resonators with extremely high quality factor and acceptable cost is currently the main challenge. Here, we demonstrate the application of ultrafast laser in manufacturing of three-dimensional (3D) FS micro hemispherical resonators with unrestricted edge

In this work, experimental data and finite element analysis reveals deflection in diaphragm supporting material leading to non-linear pressure-reflection response. These results are contrary to the standard assumptions presented in literature, where modelling of deflection response in diaphragm pressure sensors is primarily carried out assuming a rigid supporting structure. An extrinsic fiber-optic

Neural interfaces bridge the nervous system and the outside world by recording and stimulating neurons. Combining electrical and optical modalities in a single, hybrid neural interface system could lead to complementary and powerful new ways to explore the brain. This convergent approach has gained robust and exciting momentum recently in neuroscience and neural engineering research. Here, we review

This paper presents a novel LC-based passive wireless flexible pressure sensor that employs microstructured ferromagnetic films with tunable effective permeability. The proposed device consists of a micromachined planar spiral coil and a polymer film with cilia arrays (CAs) realized by the ferrofluidic instability principle. The effective permeability of the polymer film can be tuned by deforming the

Over the past two decades, researchers have advanced and employed integrated microfluidic circuitry to enable a wide range of chemical and biological ‘lab-on-a-chip’ capabilities. Yet in recent years, a wholly different field, soft robotics, has begun harnessing microfluidic circuitry as a promising means to enhance soft robot autonomy. Unfortunately, key challenges associated with not only the fabrication

In this paper, a novel micro-tensile testing apparatus is designed and built to characterize the micromechanical behavior of materials. Furthermore, a special geometry for micro specimens is introduced that could facilitate problems related to the handling, gripping, and aligning such specimens. The device can be integrated with an optical microscope to observe the microstructural evolution taking

Nano-resonators are increasingly used to study fundamental phenomena in dynamical systems. Strain tuning of resonance frequency provides an additional control knob in experiments that use these devices. In this work, we present a simple technique to tune the strain in these nano-resonators by controllably deforming a small section of the silicon substrate. We fabricate the graphene nano-resonators

Sophisticated three-dimensional microstructures fabricated using the negative tone SU-8 photoresist are used in many biomedical and microfluidic applications. Scanning electron microscopy (SEM) and profilometry are commonly used metrological techniques for the dimensional characterization of fabricated SU-8 microstructures but are not viable for non-destructive measurements and characterization of

Micro-electro-mechanical-systems (MEMS) structures with different in-plane dimensions often need to be released simultaneously from the bulk of the wafer and a single dry etching or wet etching technique cannot fulfill all release requirements. In this paper we present a universally applicable solution to release MEMS structures with different surface areas in a controlled and uniform way, which combines

Label-free cell separation is a promising method in the field of stem-cell research to obtain desired cell populations. Here, we report on phospholipid polymer-coated microfluidic channels with immobilized antibodies as devices for the capture of cells expressing target antigens in a label-free manner. We fabricated a microfluidic channel containing immobilized antibodies against vascular endothelial

A lot of mechanical energy is lost in the braking process of automobiles, and it is feasible to harvest the energy and power electronic devices by using the technology of a triboelectric nanogenerator (TENG). In this study, we propose a pulsed freestanding TENG (PF-TENG) with a grid structure to harvest mechanical energy in the braking process, and use electric brushes to achieve a unidirectional pulsed

Flexible electronics require more compact interconnects for next-generation devices. Polymer devices can be bonded to integrated circuit chips, but combining flexible and rigid substrates poses unique technical challenges. Existing technologies either cannot achieve the density required for modern chips or employ specialized equipment and complex processes to do so. Here, we adapt several approaches

Shock-free ion transmission from atmospheric pressure to a microelectromechanical system (MEMS)-based mass spectrometer has been achieved using micro-engineered nickel skimmers. The signal level has increased 70-fold compared with a previous configuration in which the skimmer did not sample the supersonic flow. The skimmers are formed by electroplating internal surfaces of anisotropically etched, pyramidal

The 3D bio-printing has been developed as an effective approach to artificially create tubular tissue structures, which have been frequently found in body and organ systems. China Agricultural University (CAU) has developed a laboratory 3D bio-printer that can create tubular structures with the encapsulation of microfluidic channel. In order to create a tubular structure with more effective micro-channel

Micro-droplet ejection is a liquid dispensing technology that has potential applications in many fields. Specifically, pneumatic ejection is actuated by a solenoid valve, which is set to ‘conduction’ state for a brief period of time Δt. High pressure gas of P 0 enters the liquid reservoir, then releases through a venting tube, creating a oscillating pressure waveform P(t), forcing the liquid out through

Diverse wetting contrasts of binary wettability patterns in nature have inspired a versatile platform for microfluidics manipulation. To date, nevertheless, building a binary wettability patterned micro/nano structure with highly ordered configuration has inevitably brought wettability contamination challenges in interface control. Herein, this work studied a facile approach to fabricate permanent

A high-accuracy differential resonant pressure sensor with two similar resonators is proposed using the linear fitting method to guarantee its output linearity without polynomial compensation. Results reveal that the nonlinearity of the differential resonant pressure sensor is largely dependent on the tensile/compressive sensor pressure–stress ratio c when two similar resonators are used separately

This paper presents a dual-frequency piezoelectric micromachined ultrasonic transducer (PMUT) line array with low crosstalk level, which was fabricated on silicon-on-insulator (SOI) wafers with sputtered piezoelectric thin film (PZT) and Si diaphragm structure. The obtained array consists of 120 of 0.77 MHz and 192 of 2.30 MHz PMUT units in total with minimum interspace of 50 μm. Due to the high piezoelectric

The weakly coupled resonators based on mode localization are promising in emerging signal measurement fields due to the verified relative mechanical sensitivity enhancement and exceptional ambient robustness. In this work, we report a novel mode localized artificial hair sensor for dual-axis air flow sensing. A new full-scale linear output metric based on differential subtraction of reciprocal amplitude

Residual stress gradients often negatively affect the performance of MEMS devices, causing film curvature and changing the designed gaps of released structures. In this work, we built folded beams designed to compensate for the film curvature and keep the actuator gaps of sensitive resonant switches constant. While the average stress gradient is cancelled by our designs, we find that random variations

In this paper, a novel optimization method, in which composed of the genetic algorithm, particle swarm optimization (GA–PSO) and improved gradient descent algorithm, are used to conduct a double-objective optimization for the U-shaped actuator. In the procedure of optimization, two objectives, i.e. force and displacement, and four main sizes are utilized. Before, the deep reactive-ion etch (DRIE) technology

A recoverable self-cleaning surface is studied by coating the nanostructured core–shell microcapsules like a chestnut bur. The microcapsules encapsulate the hydrophobic agent so that when they are broken by mechanical damage, it is released and functions to recover the loss of the self-cleaning performance. The core–shell droplets encapsulating the hydrophobic agent are generated continuously by introducing

Silicon-on-insulator (SOI) wafers are used in many micro-electromechanical system (MEMS) devices because of their stable mechanical properties. However, one of the disadvantages of using the SOI configuration is residual stress deformation; strong residual stresses in the buried-oxide layer deform the device and deteriorate its performance. This could prevent the development of high-precision sensors

Two orthogonal standing acoustic waves, generated by piezoelectric excitation, can form a two-dimensional pressure field in microfluidic devices. A phase difference of the excitation waves can be employed to rotate spherical m-sized silica particles by a torque mediated through the viscous boundary δ around the particle. The measurement of the rotational rate is, so far, limited to high-speed cameras

This paper reports a novel MEMS accelerometer whose effective stiffness can be adjusted flexibly and even tuned to almost zero by using the electrostatic softening effect of two parallel plate capacitors: the comb-finger capacitor and the triangular capacitor. When applied to a biased voltage, the comb-finger capacitor provides a relatively large and nonlinear negative stiffness in the gap-varying

A serial flexible humidity sensor based on graphene oxide (GO) fiber and quartz crystal resonator (QCR) was proposed. The serial sensing structure was formed by electrically connecting the QCR with GO fiber embedded in textile in series. This structure became more adjustable by separating the transducing part and sensing part. The feasibility of the serial sensing structure was verified by simulation

This work presents three new narrowband radio frequency (RF) microelectromechanical systems (MEMS) filters made from mechanical or electrically coupled resonators with a quality factor Q of over 10 000. A low-stiffness rectangular-frame mechanical coupling beam (RFCB) is designed, and a filter with an RFCB is successfully developed with a center frequency of 75.5 MHz and a percent bandwidth (BW) of

A tunable threshold pressure sensor based on parametric resonance of a microbeam subjected to electrostatic levitation is proposed. Parametric excitation can trigger a large amplitude vibration at twice the natural frequency if the magnitude of the driving force is large enough to overcome energy loss mechanisms in the system such as squeeze film damping. This causes a temporarily unstable response

Despite significant demand for penetrating intracortical neural probes (PINPs), challenges remain regarding their biocompatibility and stability due to the mechanical mismatch between brain tissue and PINPs. Here, we propose a promising UV patternable polymeric material for PINPs and a design criterion for optimizing the geometry of polymeric PINPs. UV-curable polysiloxane acrylate (PSA) shows remarkably

One of the most important responsibility of manufacturers is to protect their products against counterfeiting. Currently there are a large variety of protection methods based on security tags that can be attached to the products such as holographic labels, nanoparticles, encrypted messages, barcodes etc. The research in this area focuses on the possibility of adding extra security elements (ex: nanoparticles)

In this paper, the serpentine-shaped semi-packed chromatographic columns embedded with the micro-post array were developed to separate the characteristic markers of advanced fibrosis. The 3 m long micro separation columns with a rectangular channel cross-sectional dimension of 250 μm 200 μm and the micropost diameter of 30 μm were prepared by the micro-electromechanical system (MEMS) technology. Based

This paper reports a silicon-chip based electromagnetic (EM) vibration energy harvester that is fabricated with a wafer-level micro-casting technique to form on-chip integrated 3D metal solenoids and magnet sliding channels. Many solenoids of 150-turn coil are simultaneously formed by filling molten ZnAl x alloy into the pre-micromachined solenoid moulds in one wafer within 7 min. After saw dicing

Rare cell sorting with magnetic nanoparticles labels (MNPs) has been achieved by the aid of microfluidic chip, which offers an easy processing approach to sort the rare cells from a trace original sample. However, its applications have been limited in large part due to the presence of some redundant MNPs in the sorted target cells affecting the purity of sorted target cells. This paper demonstrates

This paper presents the microfabrication and testing of a membrane-free eight-element single-polarity (n-type) sensing rosette integrated with strained silicon technology over (111) silicon plane to measure the full 3D stress/strain tensor with full temperature compensation. Such n-type piezoresistive (PR) sensor has low sensitivity to the out-of-plane components compared to the in-plane components

Intraocular pressure (IOP) is a crucial physiological indicator for the diagnosis and treatment of glaucoma. The current infrequent IOP measurement during an office visit is insufficient to characterize the symptoms. Here, an LC resonator strain sensor in a contact lens, composed of a stretchable inductance coil using liquid metal and a chip capacitor, was developed for real-time IOP monitoring. The

Within this work, we demonstrate a method for the etch-less, additive microfabrication of TiO2 thin film layers on top of the medical implant material titanium grade 23. A combination of common UV-lithographic microfabrication and a subsequent anodic oxidation process allows the direct additive fabrication of microstructured oxide layers on top of the bulk base material without the use of any additional

Polymer micropillar structures have been used as microsensors and microactuators in scientific studies. In these studies, the deformation of the micropillar is used to estimate the forces applied on the micropillars from the external environment, or the forces generated by the micropillars. The accuracy of such force calculations depends on the accurate estimation of the structure’s spring constant

The microrobot, which can address the fuel depletion and wire limitation, has exhibited great potential in the fields of lab-on-chip devices, sensing and monitoring devices, and some biomedical applications. In this paper, a dual-driven wireless microrobot, which can harvest and convert external optical and magnetic energy into the kinetic energy, is described. The dual-driven microrobot is fabricated

Additive manufacturing for microfluidics shows potential to boost research and development in research biology and molecular diagnostics. This paper reports on novel process and material optimisation techniques in the creation of a monolithic microfluidic chip geometry for polymerase chain reaction (PCR) thermocycling using stereolithography (SLA). A two-stage printing protocol with projection SLA

This paper reports the design, microfabrication, and experimental evaluation of a monolithic Si-micromachined four-stage Knudsen pump (KP) suitable for microscale gas chromatography (GC) applications. Without moving parts, KPs generate gas flow by leveraging free molecular flow against a temperature gradient in narrow channels. In this work the KP consists of four monolithically integrated stages that

Near-field electrospinning (NFES) is an additive manufacturing technique that allows for both high-resolution 3D structures and a wide variety of printed materials. Typically, a high electric field between a nozzle, the spinneret, and the substrate creates a μm-sized jet of a supplied liquid material. With mm distances between spinneret and sample, it is possible to have a fair control of the lateral

This study developed a small, three-axis force sensor with a 3D microstructure for installation into a robot gripper. The sensor was manufactured by high-temperature punch creep-forming of 5 μm thick single-crystal silicon (Si) cantilevers during an impurity diffusion process for piezoresistors. The punch creep-forming could achieve a large out-of-plane deformation of the Si cantilevers within a small

Soft actuator is widely applied in soft grasp and artificial actuation. However, the characteristics of fast response and precise controllability are challenges for soft actuators. In this report, an ultrafast response and precisely controllable soft electromagnet actuator based on Ecoflex rubber film filled with neodymium-iron-boron is proposed. After optimizing the matrix and size of the actuator