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

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