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

A process able to produce at wafer scale patterned electrodes on the vertical sidewalls of trenches is described and investigated in detail. It is based on metal evaporation at oblique incidence through a shadow mask made in a dry photoresist film. A full model of the deposition and patterning process is established in order to map the shape as well as the thickness and density of patterned electrodes

In this article, we propose a process to fabricate micromachined hotplates, by leveraging the multiuser MEMS process known as PolyMUMPs from MEMSCAP. The PolyMUMPs technology is complemented through self-aligned post-processing steps. This procedure eliminates the requirement of aligning masks during post-processing and enables easy prototyping of microhotplates. Two designs were fabricated, including

Powered microvalves are necessary for a variety of microfluidic applications such as on-demand droplet generators and droplet capture systems. Currently, a central challenge for these microvalve systems is the miniaturization of bulky power sources and control components, for example, air compressors, hydraulic pumps, solenoid valves, and regulators. In this paper, we propose a polydimethylsiloxane

This paper describes a MEMS triaxial gyroscope utilizing three-dimensional piezoresistive elements. MEMS gyroscopes are widely used for robot motion control, drones, mobile phones and so on. Although a piezoresistive sensing element has the potential for high sensitivity to angular velocity via vibrations that occur due to the Coriolis force, a commonly used piezoresistor, which is formed on a device

The development of microelectrode arrays (MEAs) along with complementary advances in electronics, mechanics and software to connect with these arrays has led to the in vitro interfacing and benchtop electrophysiological models of several electrically active cells such as neurons and cardiomyocytes proving vital models and testing of human disease conditions in a dish/on a chip. This topical review

This work presents a self transformed method of ordering random buckles in thin metal film fabricated on soft elastomeric film for reliable MEMS devices. Detailed modeling of thin metal film buckling and buckle manipulative stresses associated with the self transformed film is investigated. In this study, a thin metal Au film deposited with dc sputtering is used as a strain sensing film on an elastomeric

Reducing geometry size of lithium niobate (LN)-based photonic elements is imperative for realizing ultra-compact LN photonic systems with novel functionalities. However, precision fabrication of LN structures of tens-of-nanometers and below is a challenging task. Focused ion beam (FIB) is promising for ultra-smooth LN nano-patterning due to its flexibility and high resolution. However, tremendous surface

Fabrication of suspended pyrolytic carbon 3D-microstructures from SU–8 was studied in variable pyrolysis temperatures. The dimensions of suspended parts were from 3 µ m to 1500 µ m in length with one to four anchor points. The pyrolysis temperatures were 800 °C to 1100 °C, and the resulting pyrolysed carbon structures were analyzed in terms of shrinkage, surface roughness, electrical resistivity and

This paper describes a novel, multilayered hot embossing method for fabricating a microstructure pattern on various polymer substrates. The method involves a multilayered hot embossing process with three polymer substrates (polycarbonate, polymethyl methacrylate, and low-density polyethylene), three pieces of microstructured molds, and graphene-based heaters. Only one hot embossing step is required

This paper presents an analytical model to estimate the actuation potential of an electrostatic parylene-C diaphragm, processed on a glass wafer using standard microelectromechanical systems (MEMS) process technology, and integrable to polydimethylsiloxane (PDMS) based lab-on-a-chip systems to construct a normally-closed microvalve for flow manipulation. The accurate estimation of the pull-in voltage

A new and improved approach using vertical combs for the differential capacitive sensing of acceleration using silicon-on-insulator (SOI) wafer technology is presented. The design, which supports a ± 30 g operational range demonstrates the enhanced linear range that is achievable using an SOI approach, which overcomes the limitations of the dissolved wafer process (DWP) technology based on the diffusion

The ability to characterize tactile perception will be crucial to the effective use of tactile information in the next generation of information communication technology. Tactile perception depends on multiple properties of the surface being touched, including surface texture, stiffness, and temperature. To quantitatively evaluate the contribution of each individual property to tactile perception,

Piezoelectric actuators are well known for their high precision, and are promising for applications in microrobotics, drug delivery and nanopositioning. However, a piezoelectric traveling wave ultrasonic micromotor is very hard to control due to the frictional drive principle. This work introduces a closed-loop control strategy for a micromotor. An integrating on-chip structure with a piezoelectric

Soft and flexible sensors have great potential to be integrated into robotic mechanisms, for example, the prosthetic finger. Liquid conductive metals as a promising class of materials could be used to fabricate these sensors because they can undergo large deformations while retaining good electrical conductivity. Herein, commercial silicone surgical tubes with their own tubular structure are applied

Electronic and information hardware is developing in the direction of lightweight products, miniaturization, and integration. The transformer is still the most effective solution for signal isolation and power transfer. In response to the key problems of microtransformer fabrication, this paper presents a hybrid method for fabricating micro/nano structures via femtosecond laser wet etch technology

Among the advanced integrated circuit (IC) integration methods, three-dimensional heterogeneous integration with through-silicon via (TSV) technology showed great potential towards the system-level integration with an increased interconnect density in a smaller footprint. However, the heat mitigation across several dies remains a critical issue in this technology with the utilization of vertical dimension

An anodic bonding model of Si/SiO 2 -glass is established and demonstrated. In the theoretical part, charge movement in Si/SiO 2 -glass anodic bonding is studied in detail. On this basis, an equivalent circuit model of anodic bonding with SiO 2 structure is established. By solving the corresponding Poisson equation, the formulas for the width of the depletion layer and the electrostatic force during

A mathematical model of an ultrahigh sensitivity piezoresistive chip of a pressure sensor with a range from −0.5 to 0.5 kPa has been developed. The optimum geometrical dimensions of a specific silicon membrane with a combination of rigid islands to ensure a trade-off relationship between sensitivity (S samples = 34.5 mV kPa −1 V −1 ) and nonlinearity (2K NL samples = 0.81%FS) have been determined.

The analytic equations of mass flow rate for gas flow in microchannels or microtubes developed in the 1990s have been widely validated by experimental results for slow-speed flow, but the applicability for high-speed flow might be constrained. A new model for analyzing the modified Navier–Stokes equations of the gas flow in 2D microchannels and microtubes is proposed in this study, named the simplified

The patterned fluoropolymer film hydrophobicity and colored oil layer uniformity were critical for electrofluidic displays. Typically, reactive ion etching (RIE) is commonly used to pattern fluoropolymer films due to the chemically inert nature of fluorinated materials. However, the RIE process permanently changed the surface properties of the fluoropolymer film. These affect the function of the electrofluidic

In the present study, we report a microfluidic platform that enables real-time control of biochemical stimuli to biological cells. The microfluidic platform is designed by integrating a ‘Christmas tree’ inlet for pre-generating spatially linear concentration gradient, with a Y-shaped channel to modulate dynamic signals with an external programmable air pump. The proposed design is simple and straightforward

In this work, ZnO/Al thin film based flexible acoustic wave devices are demonstrated for their applications in gas flow rate measurements based on the changes in temperature of the devices. A good sensitivity of gas flow rate can be achieved, mainly because thin film based device has a large temperature coefficient of frequency of ∼280 ppm K −1 , owing to the large coefficient of thermal expansion

This paper reports an electromagnetic oscillation flexible printed circuit board (FPCB) micromirror based scanning triangulation laser rangefinder (LRF). The FPCB micromirror has a large aperture (8 mm × 5.5 mm) and high flatness (radius of curvature, ∼ 15 m), that overcomes conventional MEMS micromirrors’ limitation of a small aperture size (less than 5 mm). Subsequently high power lasers with large

Traditionally, polymeric microcantilevers are assembled by a multitude of process steps comprising liquid spin-coated photoresists and rigid substrate materials. Polymer microcantilevers presented in this work rely instead on commercially available dry film photoresists and allowed an omittance of multiple fabrication steps. Thin, 5 μ m thick dry film photoresists are thermally laminated onto prepatterned

The repeatability of manufacturing process is one of the prerequisite aspects in printed electronics. Particularly, the requirement for the positioning accuracy becomes severe as the miniaturization of printed traces develops, patterning area enlarges, and potential applications widen. Therefore, a measure to quantify the effect of various processing parameters on the global registration error of printed

The drift phenomena of closed-loop capacitive silicon-based micro accelerometers have been hindering their application in the area of precise and rapid industrial positioning, which especially requires a good dynamic performance. Using both theoretical methods and experiments, this paper will systematically investigate the underlying mechanisms of such phenomena. The possible causes of drift, including

In this work, a novel method to fabricate transparent nanomesh-structured hydrophobic (TNH) films was developed to improve the optical properties by minimizing light scattering. First, a nickel nanomesh mold was prepared using phase-shifting edge lithography. Subsequently, the TNH film was fabricated by nanoimprinting an ultraviolet-curable fluorinated polyurethane resist. The resist had a water contact

This paper investigates the responses of initially curved micro-beams subjected to an electrostatic excitation. A Euler–Bernoulli beam theory is utilized to derive the governing equation of motion. A reduced-order model was developed by discretizing the equation of motion using straight beam mode shapes as basis functions in a Galerkin expansion. The results show evidence of the superharmonic resonances

We describe the microfabrication and magnetic behavior of a composite/hybrid, two-dimensional, magnetostatically interacting array of nanomagnets of Fe and exchange-biased bilayer Fe/IrMn heterostructures. Such an interacting array of nanomagnets, forming an artificial spin ice lattice but with a hybrid structure, has not been demonstrated before. These devices are fabricated of epitaxially grown Fe/IrMn

Direct laser writing is a lithography technique for fabricating features in sub-micron dimensions. Major advantages of this technique are the elimination of mask, cost-effectiveness and design scalability. Patterns with different dimensions and geometries can be fabricated using this technique, which are greatly influenced by several laser parameters such as the intensity of the laser, speed of the

A novel type of microfluidic absorbance cell is presented here that inlays black poly(methyl methacrylate) (PMMA) into a clear PMMA substrate to realize an isolated optical channel with microlitre volumes. Optical measurements are frequently performed on microfluidic devices, offering effective, quick, and robust chemical analysis capabilities on small amounts of sample. Many lab-on-chip systems utilize

Sensors exploiting long-range surface plasmon polariton (LRSPP) waveguides comprised of Au stripes embedded in Cytop with integrated and encapsulated microfluidic channels are fabricated and demonstrated. A fabrication approach was devised where the lower cladding and recessed Au stripes are fabricated on a Si supporting substrate, and the upper cladding and microfluidic channels are fabricated on

This paper presents the analytical modeling, simulation and experimental validation of sensitivity, temperature variation and active controllability of MEMS geometric anti-spring (GAS) devices. Two models, the elasticity model and the thermal drift model, were proposed and analyzed, based on the study of asymmetrical and symmetrical geometric anti-spring structures. With the elasticity model, structural

The hot embossing process is a cost-effective replication technology for the fabrication of polymeric micro/nano-structures. Nevertheless, there is a need to reduce the embossing temperature as industrial applications of the hot embossing process are limited by the high temperature required. For amorphous thermoplastic polymers, the hot embossing process can be conducted below the polymer’s glass transition

In the research of flexible pressure sensors supported by three-dimensional skeleton structure, the combination of nanomaterials and skeleton structure is a difficult problem to be further solved. Herein, a piezoresistive sensor based on the graphene-PDMS @ sponge is prepared by fixing graphene on a sponge skeleton using PDMS. The as-prepared piezoresistive sensor exhibits high elasticity (strain up

Enhanced optical spectral resolution is of great interest for sensor technology applications. One-dimensional scanners are commonly used for spectral imaging, and there is increased interest in 2D spectral imagers. The latter are not easy to achieve, since single channel pixels need to be very small and creating an arbitrary filter of pixel size is not trivial. Here we present a single mask etch step

The phenomenon of Marangoni chaotic electroconvection of electrolytes induced by liquid metal droplets has been serving as a method of choice for pumping of microfluidics in the past ten years. Although an external additional alternating voltage, usually being sufficiently small, was invariably employed in practical experiments for stabilizing the unidirectional liquid motion caused by a preexisted

We introduce a multi-step microfluidic reactor for the synthesis of hybrid nanoparticles. As part of this study, nanoparticles composed of chitosan and iron-oxide are synthesized at room temperature by forming sequential droplets of reagents in the microreactor followed by merging and mixing them in a step by step process. The obtained nanoparticles were characterized by transmission electron microscopy

This paper presents an accurate and complete analysis of the dynamic performance of a V-shaped microactuator. This multi-physical coupling analysis is split into two steps: the electro-thermal sub-model for temperature distribution and the thermo-elastic sub-model for displacement. For the electro-thermal sub-model, a combination of the Chebyshev spectral method and the improved Euler method is utilized

In order to fabricate intact and precise ceramic microcomponents applied in microelectromechanical systems (MEMS), thermo-responsive poly( N -isopropylacrylamide) (PNIPAAm) brushes are grafted onto poly(dimethylsiloxane) (PDMS) micromolds by visible light-induced polymerization. The application of PDMS-Br@PNIPAAm micromolds in soft lithographic fabrication of ceramic microcomponents is demonstrated

3D elliptical vibration-assisted cutting (EVC) is a method for rapidly creating ultra-precision free-form surfaces with features at the micro-scale, which have a wide array of industrial applications. Displacement coupling and low stiffness limit the applications of current 3D EVC mechanisms in machining difficult to cut materials and precise micro-features. To overcome these limitations and improve

An eccentric reflective optical fiber micro-electro-mechanical system (MEMS) micro-pressure sensor is proposed in this paper. The core part of the sensor consists of a dual fiber collimator (a fiber collimator with two pigtails) in an eccentric position and a sensitive silicon diaphragm. The sensitive silicon diaphragm adopts the BM (beam-membrane) structure with small structural parameters manufactured

ZrO 2 ceramic has a wide range of applications, such as in the thermal barrier coating (TBC) of turbine blades, micro actuators, and gas sensors. However, this material is challenging to machine due to its high hardness and brittleness. Although spark assisted chemical engraving (SACE) can be used to machine ZrO 2 ceramics, the traditional SACE models for glass are difficult to apply to ZrO 2 ceramics

The controlled biofabrication of stable, aligned collagen hydrogels within microfluidic devices is critically important to the design of more physiologically accurate, longer-cultured on-chip models of tissue and organs. To address this goal, collagen-alginate microgels were formed in a microfluidic channel by calcium crosslinking of a flowing collagen-alginate solution through a cross-channel chitosan

This paper proposes an innovative nanoimprinting method that features imprinting a single droplet of resist and spreading it from center to edge to fully cover a full wafer substrate. Important advantages of this type of nanoimprinting include avoiding air bubble trapping, forming conformal mold/substrate contact, minimizing residual layer thickness, and saving the amount of resist being used. It also

The rotation of the helical micromachines can produce efficient motion efficiency at small-scale conditions and have the potential for multi-field applications. In this study, we propose self-scrolling schemes aiming at a flexible bilayer structure that includes the strained layer and magnetic layer. The magnetic layer is composed of magnetic nanocomposites and can respond to an external magnetic field

Micro-electromechanical-system (MEMS) based actuators, which transduce certain domains of energy into mechanical movements in the microscopic scale, are increasingly contributing to the areas of biomedical engineering and healthcare applications. They are enabling new functionalities in biomedical devices through their unique miniaturized features. An effective selection of a particular actuator, among

Micro-dimples are a specific class of surface textures that are ubiquitous in a wide range of applications where functionalities such as wetting, hydrodynamic drag reduction, and sliding friction reduction are needed. However, fabrication of the micro-dimples through the existing manufacturing techniques involves the use of complex equipment and requires relatively long cycle times. Consequently, we

In this study, a novel rotating permanent magnetic actuator (PMA) system is proposed to manipulate magnetic nanofluids to pump chemicals inside micro-sized channels with circular paths. The PMA consists of two permanent magnet pairs and a rotor-like structure. A semicircular-shaped microchannel with a square cross-section area is located at the top of the actuator in order to investigate the performance

Rapid, portable, and sensitive biosensors for the detection of cardiac biomarkers are important for early diagnosis of cardiovascular diseases. We demonstrate a micro-electromechanical film electroacoustic resonator for heart-type fatty acid-binding protein assays. This device combines an immunologic sensitive element with the resonator working in biological liquids. Based on the mass-sensitive mechanism

This paper reports on frequency tunable MEMS magnetoelectric (ME) sensors. Different designs are studied in respect to ME voltage coefficient and frequency tunability. Compared to state-of-the-art ME sensors, the presented ME resonators display a highly reversible and linear frequency tuning, enabled by applying a DC voltage to piezoelectric actuators. A frequency shift of up to 0.2 Hz V −1 is demonstrated

Cellular metamaterial structures with sub-micron features have shown the ability to become excellent energy absorbing materials for impact mitigation due to the enhanced mechanical properties of materials at the nanoscale. However, in order to optimize the design of these energy absorbing metamaterial structures we need to be able to measure the dynamic properties of the sub-micron features such as

The manufacture of inertial-grade and tactical-grade diamond micro electro mechanical systems (MEMS) hemispherical resonator gyroscopes is limited by the manufacturing accuracy of the monocrystalline silicon hemispherical concave mold, on which the gyroscope shell is formed. To solve this problem, this paper presents a new method for micro-ultrasonic machining of microhemispherical molds for resonator

We present a compact tunable Fabry–Pérot filter operating at mid-infrared wavelengths (3–5 µ m) with novel actuators based on liquid crystal elastomers (LCEs). These are a new class of shape-memory materials with potential for achieving large reversible actuation based on different external stimuli. For actuating the Fabry–Pérot filter, microheaters and thermo-actuated LCE layers were fabricated as