This paper reports the design, microfabrication, and experimental evaluation of a monolithic Si-micromachined four-stage Knudsen pump (KP) suitable for microscale gas chromatography ( µ 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

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 μ m-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 μ m 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

Composite materials comprising multilayers of metal and conductive polymer can have applications in sensing, biomedical, and energy storage/conversion scenarios. One attribute of such metal/polymer composites is that they typically display highly anisotropic electrical properties, which makes them useful as materials for microelectronic or magnetic devices. However, incorporating the deposition of

This paper describes both qualitative and quantitative analysis of rapid microvortex flow generation and manipulation induced by opto-electrohydrodynamic technique. A flow named twin opposing microvortex (TOMV) is generated by infrared laser light under non-uniform alternating current (AC) electric fields. For the AC electric fields, frequency ranges from 3 kHz up to 2 MHz while the voltage is changed

We developed a stent flow sensor using micro-electromechanical systems (MEMS) technology in order to measure airflow in the airways of laboratory animals. An airflow waveform contains a respiration signal produced by lung motion and heartbeats as these functions are physically connected. This enables both respiration and heart functions to be evaluated under unrestrained and unanesthetized conditions

This work presents a highly sensitive biosensor based on a microcantilever and alternating current (AC) electrothermal technology. The AC electrothermal unit was developed and integrated with the cantilever chip to improve the capture efficiency of the molecules under test. The AC electrothermal effect enhanced the aggregation of molecules around the microcantilever, increased their binding probability

In this study, Y-bifurcated microchannels fabricated from a {100} silicon in 25 wt% tetramethylammonium hydroxide water solution at the temperature of 80 °C have been presented and analysed. We studied the etching of acute angles with sides along the < n 10> crystallographic directions in the masking layer where 1 < n < 8. We considered symmetrical acute corners in the masking layer with respect to

Fine manipulation of particles is essential for the analysis of complex samples such as blood or environmental water, where rare particles of interest may be masked by millions of others. Inertial focusing is amongst the most promising techniques for this task, enabling label-free manipulation of particles with sub-micron resolution at very high flow rates. However, the phenomenon still remains difficult

This paper develops a novel processing method of plasma electrolytic oxidation-assisted micromilling (PEOAM). Electrolyte solutions with KH 2 PO 4 , NaAlO 2 , or Na 2 SiO 3 as the main component are designed, and three types of oxide films are grown on the surface of a Ti6Al4V alloy in situ by means of plasma electrolytic oxidation. The morphology and composition of the oxide films are characterized

Analyte mixing and delivery to a functionalized sensor surface are important to realize several advantages associated with biosensors integrated with microfluidic channels. Here, we present a comparison between a herringbone structure (HBS) and a curved passive mixing structure of their efficiency at facilitating mixing and surface saturation using fluorescein included in one of the inlets of a Y-channel

In this study, an image inspection method was introduced to two-arm Archimedean spiral antenna patterns to quantify and qualify their in-line integrity, which was linked to their off-line electrical characteristics in terms of the capacitance values through machine learning. The pattern was intentionally deteriorated in shape to imitate potential fabrication variations existing in the microelectronic

As tool electrodes of different materials have distinct electrical discharge machining (EDM) wear rates, this paper proposed a method for fabricating a surface microstructure by EDM with a laminated electrode including a functionally graded material foil. The preparation of functionally graded CuSn foils and the formation of a functionally graded laminated electrode (FGLE) were studied. Additionally

This paper presents the design, fabrication and characterization of a novel micro electromagnetic linear actuator, which exhibits two highlights: slider self-alignment and self-attachment capability. Such characters are realized by deliberately utilizing the attractive force between the permanent magnets (Nd 2 Fe 14 B) of the slider and nickel ferromagnetic cores embedded in the stator. Actuation is

The elastic-plastic properties of mesoscale electrodeposited LIGA Ni alloy specimens are investigated as a function of specimen size, strain rate, and material composition. Two material compositions are studied: a high-strength fine-grained Ni-Fe alloy and a high-ductility coarse-grained Ni-Co alloy. The specimens have thicknesses of approximately 200 μ m and gauge widths ranging from 75 μ m to 700

Baicalein, a kind of flavonoid, has many medical benefits, and therefore, its accurate and efficient determination is necessary in the field of medical ingredient detection. To achieve the rapid and precise detection of baicalein, a three-dimensional (3D) expansion–contraction wave micromixer was designed and used along with an electrochemical detection method to assemble a micromixing electrochemical

The modulation scheme of ultrasonic communication using capacitive micromachined ultrasonic transducers, acting as the transmitted port and received port, was simulated and experimented with four parallel channels in silicone oil. Four channel signals were coded by a steady and reliable binary amplitude shift keying method such as on–off keying modulation. The modulation scheme was simulated with additive

This paper reports a predictive model for vibration-to-electrical energy harvesters based on an in-plane, gap-closing variable capacitor with frequency up-conversion triggered by the impact between the electrodes. Since the output power is proportional to the output frequency, rectifying low-frequency ambient vibrations (1–50 Hz) to high-frequency electrical signals (200–600 Hz) increases the power

This paper describes a new design of piezoelectric micromachined ultrasonic transducer (pMUT) with a monocrystalline Pb(Zr,Ti)O 3 -based thin film (Mono-PZT) for enhancing the mechanical robustness. In this study, we investigated two design concepts to suppress crack generation in Mono-PZT. First, the area of Mono-PZT is limited by leaving an island Mono-PZT pattern only on the membrane of the pMUT

A high numerical aperture (NA) scanning digital oil immersion lithography scheme is proposed and demonstrated in this study. To successfully conduct the scanning digital oil immersion lithography, immersion oil should be removed from the photoresist layer before the development process. Also, uniformity of the projected light patterns becomes crucial in the quality of this high NA photolithography

The failure forces and fracture strengths of polysilicon microelectromechanical system (MEMS) components in the form of stepped tensile bars with shoulder fillets were measured using a sequential failure chain methodology. Approximately 150 specimens for each of four fillet geometries with different stress concentration factors were tested. The resulting failure force and strength distributions of

This paper on the reports design, fabrication and position monitoring of a micro electromagnetic linear actuator. The actuator consists of stator, slider, guide, sensors and affiliated jigs. Actuation is achieved through ampere force between two phase micro-coils (copper) on the stator and permanent magnets (thick NdFeB film) on the slider. During the slider’s movement in the guide slot, tunnelling

This paper firstly proposes an ultrasonic liquid flowmeter based on AlN piezoelectric micromachined ultrasonic transducer arrays. By detecting the transit time of ultrasonic wave, the flowmeter can measure liquid flow in small pipes (8 mm), which is difficult for traditional bulk piezoelectric ultrasonic transducers. In the flowmeter, the acoustic path and flow path are overlapped, which greatly improves

This study presents a bone conduction microphone (BCM) to detect the variation of air pressure resulted from the skull vibration. The presented BCM consists of a commercial MEMS microphone, the sensing circuits, the bulk metal, the deformable polymer diaphragm, and two printed circuit board (PCB) covers. In this design, two chambers and a vibrating spring-mass structure are hermetic sealed by two PCB

Realization of high-aspect-ratio vertical features on silicon substrates is a crucial step in the fabrication process of microelectromechanical systems devices. Therefore deep reactive ion etching (DRIE) plays an important role in the fabrication of those structures. Recently many efforts have been made in order to propose the novel DRIE processes in order to achieve higher aspect ratios; however,

This paper presents 3D Fabry–Pérot (FP) cavities fabricated directly onto cleaved ends of low-loss optical fibers by a two-photon polymerization (2PP) process. This fabrication technique is quick, simple, and inexpensive compared to planar microfabrication processes, which enables rapid prototyping and the ability to adapt to new requirements. These devices also utilize true 3D design freedom, facilitating

Understanding the behavior of water-immersed membranes in the megahertz range is critical to develop novel acoustic metamaterials compatible with biomedical ultrasound applications. Herein, we study the influence of water on the resonance frequency and quality factor near the megahertz range of silicon nitride membranes fully immersed in water using laser Doppler vibrometry. The resonance frequency

Due to the rapid development of precision micro-manufacturing technology, the connection and assembly process of precision micro devices put forward higher requirements for the volume and accuracy of micro dispensing technology. In this paper, an ultra-micro dispensing method based on the surface tension is proposed. It can realize micro size feature adhesive dispensing, here, adhesive droplet volume

In this paper, we describe a novel fabrication method of a microfluidic integrated surface plasmon resonance (SPR) gold chip based on a (3-mercaptopropyl) trimethoxy silane (MPTMS) self-assembled monolayer. This monolayer was formed at the surface of a microfluidic chip made of polydimethylsiloxane (PDMS). Its presence was confirmed by contact angle and Fourier transform infrared spectroscopy measurements

The design, fabrication, and testing of a microelectrode array for chronic in vivo stimulation of the rat retina is presented. Epiretinal positioning of the array introduced design challenges associated with the surgical implantation approach into the rat ocular orbit. These anatomical and surgical challenges were overcome using microfabrication of thin-film Parylene C and platinum to create the array

Mechanical forces play important roles in the biological function of cells and tissues. While numerous studies have probed the force response of cells and measured cell-generated forces, they have primarily focused on tensile, but not shear forces. Here, we describe the design, fabrication, and application of a silicon micromachined device that is capable of independently applying and sensing both

The wettability transition of an ion-beam-etched micro-pillar array surface is reported in the present study. The micro-pillar array, made of negative photoresist SU-8, was fabricated by ultraviolet lithography. The results indicate that the combination of the micro-pillar array and ion-beam etching technique can easily regulate surface wettability, which can be changed from hydrophobicity to super-hydrophilicity

Recent experimental studies have shown that lateral particle migration can be controlled passively using stratified flows of co-flowing streams. In this study, we numerically analyze particle migration in a stratified Poiseuille flow of two liquids of different viscosities. A novel numerical approach using immersed boundary method is employed to perform 2D simulations in moving frame of reference.

In this paper, we propose a thermal wind speed sensor Verilog-A model with thermal-fluid-electric hybrid characteristics. Because the structure of the thermal wind sensor and the interface circuit chip are designed separately, which cannot effectively carry out MEMS-IC (integrated circuit) co-simulation, the overall performance of the sensor and interface circuit chip is prone to large deviation. At

Measurement in liquid media is a major challenge in real-time detection using resonant cantilevers. This is addressed in the present study by fabricating sub-micron thick cantilevers followed by functionalization for biomolecule detection. The fabricated cantilever resonator beams of thickness 165 nm were used for measurements in two systems: (i) human immunoglobulin (HIgG) as the antibody on the cantilever

In this study, we have proposed volume-preserving strategies to boost chaoticadvection and improve the mixing efficiency of serpentine micromixers. The proposed strategies revolve around the point that the volume of the micromixer is kept constant during the manipulation. The first strategy involves the utilization of a nozzle-diffuser (ND) shaped microchannel. Using this, the velocity of the fluids

While electrospray devices have been used in a variety of applications for decades, they have recently seen a surge in research within the field of electric propulsion. These research efforts have helped significantly improve the understanding of electrospray thruster operation and optimization, however they have primarily been focused on capillary-based, droplet emitting devices due to the more readily

Stencil contact printing is widely used to fabricate conductive patterns, and it is particularly used with solder paste to create interconnections. However, stencil contact printing is becoming inefficient for electronic components owing to the ever decreasing size of the components. An alternative method for fine pattern formation is screen printing, i.e. gap printing with a screen mask, which exploits

We developed a lead zirconate titanate (PZT) thin film actuator integrated with buried piezoresistors for the dynamic and static deformation sensing of a PZT MEMS actuator. We demonstrated the fabrication of sol-gel deposited PZT thin film devices combined with buried piezoresistors and proved, for the first time, the process compatibility of these materials. Dopant concentration measured by secondary

A double-layer flexible sensor array with an active thermal insulation method for fluid wall shear stress was fabricated in this study and evaluated experimentally. Static calibration of the sensor was studied in both wind and water tunnels and the experimental results reveal that the sensor’s static performance was improved by active thermal insulation. Compared to single-layer methods, the static

This technical note reports a rapid technique to post-process and assemble micro-components onto dies including released movable microstructures. The method is applied to microelectromechanical systems (MEMS) chips that were fabricated using a commercial process, PolyMUMPs from MEMSCAP. It allows the assembly of a micro-polyhedron over released micromotors and ensures that the micromotors remain fully

In this paper, a novel method to fabricate quartz glass electromagnetically actuated ring resonator for gyroscope application is presented. Sacrificial supporting structures were employed for the fabrication. The fabricated device was electromagnetically driven at resonance, with the resonant frequency of 42 KHz. The Q-factor at the atmospheric pressure was about 142. The frequency difference between

The triboelectric nanogenerator (TENG) has been demonstrated to be a promising technology for harvesting mechanical energy and powering electronic devices. However, it is difficult to make TENG output stable because of the irregular movement of actual mechanical sources in the environment, and the inefficient energy utilization limits its application. In this study, we propose a contact-separation

Organ-on-chip models, known as microphysiological systems, are created to mimic the anatomy and physiology of a human organ at the micro-level. Besides being pivotal in the reverse engineering of human organs and pathogenesis studies, they serve as an alternative to animal testing and the development of pharmaceutics. Monitoring the extracellular stromal environment is the basis for gaining in-depth

We experimentally investigate the removal of several microns thick plasma-enhanced chemical vapour deposition SiO 2 films by a localized dynamic fracture due to confined laser–matter interaction with the silicon substrate (punching) using 10 ps laser pulses at 355 nm. A near order of magnitude increase in the punching threshold fluence (from ∼0.1 to ∼1 J cm −2 ) is observed as the ratio between the

A microfluidic chip driven by capillary force has the advantage of low cost and ease of manufacturing in batches, and its flow behavior is dominated by the geometry and surface characteristics of the microchannel. The design of mirochannel structures is very important for the microfluidic chips. This study presents a semi analytical method for the design of capillary microchannel. In this method, the

Silver nanowire (Ag NW) is used as an attractive alternative material to fabricate flexible transparent conductive electrodes (TCE) instead of indium tin oxide, which has brittle characteristics and unstable processing expenses. For practical applications of Ag NW TCE, a proper patterning process is essential because the Ag NW layer is usually formed from the solution process. Laser ablation is one

Applying an external electric field over a polarizable electrode or object within microchannels can induce an electric double layer (EDL) around channel walls and create induced-charge electrokinetics (ICEK) within channels. The primary consequence of the induced charge is the generation of micro-vortices around the polarizable electrode or object, presenting great potential for various microfluidic

We report on a novel rapid prototyping approach for the manufacturing of highly individualized lab-on-chip (LoC) cartridges from generic polymer parts by laser micromachining and laser welding. The approach allows an immediate implementation of microfluidic networks, components, and functionalities into an existing LoC platform without the need for an expensive and time-consuming fabrication of production

High-aspect-ratio microstructures have broad application prospects in many fields. Conventionally, lithography and etching processes are the primary methods for fabricating high-aspect-ratio microstructures on glass or silicon chips. However, as application scenarios have expanded, polymeric microstructures have received increasing attention, due to the low cost and wide ranges of special physical

In this research, the Si thin wire has been assembled on a glass trench to be a bridged resonator, which has the potential to measure multi-dimensional force by the combination of strain sensing and field effect transistor (FET) sensing using the mechanical vibration. The Si thin wire was designed to be the suitable structure to improve the detectable minimum force and measurement time. Analysing the

Micro/nano-electroforming has received considerable interest from various industry sectors as an advanced micro-manufacturing technique that offers high dimensional precision and replication accuracy. When tight feature tolerances and miniaturized geometries are required, electroforming provides unique advantages and cost-effective characteristics for fabrication. This paper firstly reviews the historical

The integration of high-resolution conductive structures into polymer devices using a low-cost, rapid, and accurate manufacturing technique is important for the future of the microfluidic, photovoltaic, flexible printing, and organic electronics industries. In this study, the microcontact printing ( μ CP) of high-resolution conductive patterns on polymer substrates using silver nanoparticle inks and

Ceramic cores determine the moulding accuracy of a turbine blade’s cavity, which strongly affects thermal diffusion performance and the service life of a turbine engine. To get a high quality ceramic core after the preliminary process, this paper deals with a laser trimming technology for ceramic casting cores via double picosecond laser scanning for the first time. Instead, the core ceramic foils

The development of flexible electronic devices has primarily been focused on the production of flat 2-dimensional sensors and has lacked the ability to manufacture devices with complicated 3-dimensional geometry. A mold-based method for manufacturing devices with 3-dimensional geometry that is cost-effective and repeatable is presented herein. This technique is demonstrated by the fabrication of a

In the present study, we fabricate a hydrophobic film using a roll-to-roll technique capable of large-area continuous production and examine the film’s applicability to solar panels. The hydrophobic film was fabricated using a polyurethane-acrylate (PUA)-based UV-curable material, which has high optical transmittance and high releasability. The roll-to-roll system used in this study was custom manufactured

This paper presents a fast stamp method for fabricating Au mico/nano structures based on subtractive cold-welding transfer printing. Cyclo-olefin polymer (COP) was used as the substrate. Polymer materials such as polymethylmethacrylate, polyethylene terephthalate, polycarbonate (PC) can be used to peel off Au films from the COP substrate. Uniform micro/nanodisk patterns of a large area were fabricated

An effective development platform for custom lab-on-a-chip and lab-on-a-foil solutions has been regarded as a missing element for wider adoption of microfluidic technologies in everyday life. We have used a direct laser structuring device combined with CAD-CAM software and have developed an efficient, fast, and precise procedure for rapid prototyping of widely accessible contemporary materials utilized

A highly reliable neural interface is required in long-term neural signal recording in vivo for neuroscience research and the treatment of neurological disorders. Organic poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is a promising candidate for a next-generation neural interface material due to its better faradaic charge transfer and capacitive charge coupling than metal electrodes