Surface Micromachining Techniques Research Articles

Electrochemical jet machining in deep-small holes with gas assistance: Generating complex features on internal surfaces

Deep-small holes with internal features have important applications in thermal engineering but pose significant difficulties for traditional machining methods. Electrochemical jet machining (EJM) is an effective surface micromachining technique with numerous merits. Applying EJM to create complicated features on the internal surface of deep-small holes is attractive. However, this concept remains challenging due to the narrow and enclosed processing space. In this work, a novel gas assistance tool is developed to achieve the EJM process in deep-small holes for the first time. The hydrodynamic conditions to realize well-shaped and unsubmerged jets in both open space and deep-small holes using the specifically designed tool are investigated. The appropriate electrolyte flow rates and sidewall orifice dimensions enable the desired jet to be ejected laterally from the tubular cathode sidewall orifice. While in the deep-small hole the assist gas creates a local gas cavity around the orifice to prevent the jet from submerging, forming the jet shape required for EJM and consequently achieving localized machining of the internal surface. Excessive assist gas pressure should be avoided as it causes the jet to incline and deform, resulting in reduced machining accuracy. Furthermore, the influence of the main parameters on machining performance is examined. The developed gas-assisted EJM method demonstrates similar machining characteristics to the conventional EJM process when appropriate gas assistance conditions can produce the well-shaped unsubmerged jet. As such, various features with smooth surfaces and good shape accuracy are successfully machined on the internal surface of deep-small holes.

Fabrication and development of novel micromachined parylene-based electroactive membranes with embedded microfluidic architectures

This work describes the design, fabrication, modeling, and testing of monolithic micromachined parylene-based electroactive membranes (µPEMs) with embedded microfluidic channels. The design and modeling employed analytical plate theory to determine the optimal membrane dimensions and structural shapes for various microsystem designs. The µPEMs were fabricated using a combination of surface and bulk micromachining techniques incorporating Parylene C as a biocompatible polymeric structural material combined with patterned electrodes for actuation. Experimental actuation of the electroactive membranes demonstrated reliability with minimal voltage shifts, and theoretical pull-in voltages closely matching experimental results. Different structural parameters of the µPEMs were also tested, such as varying the overall membrane thickness/structural rigidity and actuation chamber depth. Dynamic actuation of the membrane, including, the deflection and system response to various actuation frequencies, was observed and quantified via optical coherence tomography techniques. Microfluidic architectures were monolithically integrated with the membrane actuator and successfully perfused, with no signs of leakage. This compact microsystem has potential applications in microfluidics and Lab/System-On-a-Chip devices, for use in micromixers, particle manipulators, and applying strain to adherent cells cultured on top of the membrane.

Aluminum Nitride Piezoelectric Micromachined Ultrasound Transducer Arrays for Non-Invasive Monitoring of Radial Artery Stiffness

An aluminum nitride (AlN) piezoelectric micromachined ultrasound transducer (PMUT) array was proposed and fabricated for non-invasive radial artery stiffness monitoring, which could be employed in human vascular health monitoring applications. Using surface micromachining techniques, four hexagonal PMUT arrays were fabricated within a chip area of 3 × 3 mm2. The mechanical displacement sensitivity and quality factor of a single PMUT were tested and found to be 24.47 nm/V at 5.94 MHz and 278 (in air), respectively. Underwater pulse-echo tests for the array demonstrated a -3 dB bandwidth of 0.76 MHz at 3.75 MHz and distance detection limit of approximately 25 mm. Using the PMUT array as an ultrasonic probe, the depth and diameter changes over cardiac cycles of the radial artery were measured to be approximately 3.8 mm and 0.23 mm, respectively. Combined with blood pressure calibration, the biomechanical parameters of the radial artery vessel were extracted using a one-dimensional vascular model. The cross-sectional distensibility, compliance, and stiffness index were determined to be 4.03 × 10-3/mmHg, 1.87 × 10-2 mm2/mmHg, and 5.25, respectively, consistent with the newest medical research. The continuous beat-to-beat blood pressure was also estimated using this model. This work demonstrated the potential of miniaturized PMUT devices for human vascular medical ultrasound applications.

Analysis of MEMS cantilever sensor for sensing volatile organic compounds

Increased concentration of Volatile Organic Compound (VOC) in environment can cause severe health issues and create the ozone layer at ground level. The increased concentration of ozone at the ground level creates the smog which will affect the biodiversity of mother earth, environment and human health in many ways. Many researchers have persuaded the continuous research on miniaturized sensors to detect the VOC with high sensitivity and selectivity. This paper presents the design and fabrication of MEMS cantilever sensor to sense VOCs viz., acetone (C3H6O) and Isopropyl alcohol (C3H8O). Here, the metal oxide films of Poly-vinyl-pyrrolidone (PVP) and Amino-propyl-tri-ethoxy-silane (3-APTES) having 600 nm thickness is deposited on oxidized p-type Si surface by RF sputtering process. The cantilever structure of 128 μm length, 80 μm width and thickness 600 nm is designed having a sensor area of 10,240 μm 2 . With this design specification the sensor is simulated in COMSOL Multiphysics software. Then, the sensor is fabricated using surface micromachining technique. The detection of VOCs is carried out by omnicant instrument. Here, the detection sensitivity of PVP and 3-APTES towards Acetone and Isopropyl alcohol are analyzed. The experimental results show that, PVP coated sensor performs 39% increase in sensitivity as compared to 3-APTES coated sensor to detect acetone, and 3-APTES coating sensor exhibit 7.5% increase in sensitivity to detect Isopropyl alcohol as compared to PVP coated sensor. • The cantilever sensor is designed in COMSOL Multiphysics and fabricated using surface micromachine technique. Then the fabricated sensor is tested in the omnicant instrument. By this experimentation following results and conclusions are drawn. • The coating material PVP and 3 APTES is tested against acetone and Isopropyl alcohol. The sensitivity of PVP with acetone is found 39% greater than sensitivity of 3-APTES with acetone. The sensitivity of PVP with isopropyl alcohol is 7.5% greater than 3PATES with Isopropyl alcohol. • The sensitivity of cantilever sensor is directly proportional to length and inversely proportional to the thickness of the cantilever beam. • The sensitivity is directly proportional to thickness of coated material on the sensor surface. The metal oxide film PVP is the preferable coating material to detect VOC Acetone. 3-APTES is preferable coating material to detect the Iso propyl alcohol.

THERMO-PNEUMATIC MICROPUMP FOR DRUG DELIVERY APPLICATIONS

Micropumps constitute an essential part of precise delivery and directional volume control of fluid in a microfluidic system. In biomedical applications, micropump is widely used especially in drug delivery, biological fluid transmission, organic analysis, liquid measurement, and many more. In this paper, the concept and design structure hence fabrication of the Thermo pneumatic micropump prototype are explained. The experimental measurement of the micropump employing planar diffuser nozzle in transmits fluid is also presented. Thermopneumatic micropump is comprised of three different components which are the microheater on the bottom, the flexible thin membrane that acts as an actuator, and the planar diffuser nozzle on the top to channel the fluidic. These three components were fabricated separately due to the different materials and techniques used in each component. Finally, the whole micropump system was integrated using an anodic bonding technique. Bulk micromachining technique was used to fabricated the chamber and thin-film membrane, surface micromachining technique for the microheater while replica molding technique was used for the planar diffuser nozzle. The whole diameter size for the micropump was 25 x 20 x 1.6 mm respectively. The microscope image recorded video and data was used during the experimental measurement, to observed and calculate the flow rate of meniscus motion flow in the outlet tube of the micropump. At the end of the experiment, the flow rate range of the micropump measure was approximately 770pL to 12.5nL, when the output of 2-12Vdc was applied to the microheater. This flow rate range is very suitable for drug delivery applications.

100-μm-Scale High-Detectivity Infrared Detector With Thermopile/Absorber Double-Deck Structure Formed in (111) Silicon

This article presents a 96 <inline-formula> <tex-math notation="LaTeX">$\mu \text{m}\,\,\times $ </tex-math></inline-formula> 106 <inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> sized single-crystalline silicon (SC-Si) /Au thermopile infrared (IR) detector, with the thermopile and IR absorber located at different layers of a double-deck micromechanical structure for improving detectivity. In order to enhance IR-heat absorption within such a tiny device size, an umbrella-shaped SiN IR absorbing membrane instead of traditional plane IR-absorbing film occupies the whole area of the top layer structure. The umbrella-shaped IR absorber is suspended on top of the IR-detecting thermopile layer, with a central umbrella-stick to support the suspending and conducting the absorbed IR-heat to the bottom thermopile layer. The bottom thermopile layer consists of six pairs of spiral-shaped SC-Si/Au thermocouples that feature several times higher Seebeck coefficient compared to the traditional polysilicon/metal thermocouples. By combining surface-micromachining technique with a specific bulk-micromachining process performed in (111) silicon wafer, the double-deck structured IR-detector is successfully fabricated only from the front side of a single (111) silicon wafer for IC-foundry compatible low-cost manufacturing. Testing results show that this device of about 100-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> scale achieves an ultrahigh IR detectivity of 1.01 <inline-formula> <tex-math notation="LaTeX">$\times \,\,10^{{8}}$ </tex-math></inline-formula> cm<inline-formula> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula>Hz<inline-formula> <tex-math notation="LaTeX">$^{{{1}/{2}}}\cdot \text{W}^{-{1}}$ </tex-math></inline-formula>, which is two times improvement compared to the recently reported thermopile IR detectors, though the counterparts had larger device area. Featuring tiny size and batch fabrication capability, the proposed high-performance IR-detector is promising in both single-point detection and multipixel arrayed temperature imaging applications.

Conventional surface micromachining process for the fabrication of a linear optical phased array based on piston micromirrors

Micro electromechanical system (MEMS) based optical phased array (OPA) technology generally demands narrow and tightly spaced suspended microstructures with high-aspect-ratio in the lateral dimensions. This paper presents an one dimensional OPA system which is fabricated using the standard PolyMUMPs process, leading to a low-cost, simplified and commercially accessible surface micromachining technique for the OPA technology. The proposed OPA device utilizes an array of metal-coated silicon micromirrors with high-aspect-ratio structures which act as optical phase shifters. Each micromirror along the array is individually actuated by an electrostatic parallel plate micro-actuator made of a micro-cantilever beam positioned above a fixed electrode. The field of view obtained by the device is measured as 4.76° which is comparable to those by the previous MEMS based OPA devices fabricated using custom-run and complex surface micromachining processes. The OPA device has a response time of 6.5 µs and an out of plane actuation stroke of 0.16 µm at a bias voltage of 55 V. The magnitude of the out of plane displacement by the phase shifters is equal to one-quarter of the laser wavelength (650 nm) used which leads to the desired optical phase shift of radian.

Design, Development, and Characterization of a Low Frequency CMUT-Based Anemometer

The design fabrication and development of a 67.5 kHz capacitive micromachined ultrasonic transducer (CMUT) suited for Martian anemometry is presented in this paper. To have low signal attenuation under Martian conditions, the device operating frequency is limited to 100 kHz. This is due to the low-density carbon dioxide (CO2) atmosphere and acoustic impedance mismatch transduction losses. CMUTs capable of generating frequencies less than 100 kHz need either large Silicon area or higher operating voltages. This is a problem for the battery operation and portability of devices. The devices presented in this paper are designed and fabricated using low cost commercially available surface micromachining technique. COMSOL Multiphysics and MATLAB simulations were used to analyze the device critical design parameters and investigate the operability of devices. Simulation results show that the designed single cell 170- $\mu \text{m}$ radius membrane has a resonant frequency ~65 kHz. The device exhibits a static displacement of 105nm under 20 V DC bias. Using the developed single cell model, a $3\times 10$ array CMUT anemometer was fabricated and evaluated that generates a ~65 kHz acoustic signal in lab environment. This proposed CMUT anemometer can operate for a supply < 38 V. The device performance was evaluated using a commercial air-coupled capacitive microphone named CAP1. Successful transmit-receive of ultrasound from the developed 2D array to CAP1 for separation in the range of 1–15 cm was performed. The experiment results performed in lab environment show the speed of sound and the atmospheric attenuation can be accurately measured using this developed technology with a ±5% accuracy.

Innovative Method Using Adhesive Force for Surface Micromachining of Carbon Nanowall.

The application of a carbon nanowall (CNW) via transfer is very demanding due to the unusual structure of vertically grown wall-shaped that easily collapses. In addition, direct growth on a device cannot obtain a precision-patterned shape because of the temperature limit of the photoresist (PR). Therefore, in this paper, we demonstrate a new CNW surface micromachining technology capable of direct growth. In order to reduce unexpected damage caused by chemical etching, a physical force was used to etch with the adhesive properties of CNWs that have low adhesion to silicon wafer. To prevent compositing with PR, the CNW was surface modified using oxygen plasma. Since there is a risk of surface-modified CNW (SMCNW) collapse in an ultrasonic treatment, which is a physical force, the CNW was coated with PR. After etching the SMCNW grown on PR uncoated area, PR was lifted off using an acetone solution. The effect on the SMCNW by the lift-off process was investigated. The surface, chemical, and structural properties of PR-removed SMCNW and pristine-SMCNW were compared and showed a minimal difference. Therefore, the CNW surface micromachining technique was considered successful.

A Parylene Neural Probe Array for Multi-Region Deep Brain Recordings.

A Parylene C polymer neural probe array with 64 electrodes purposefully positioned across 8 individual shanks to anatomically match specific regions of the hippocampus was designed, fabricated, characterized, and implemented in vivo for enabling recording in deep brain regions in freely moving rats. Thin film polymer arrays were fabricated using surface micromachining techniques and mechanically braced to prevent buckling during surgical implantation. Importantly, the mechanical bracing technique developed in this work involves a novel biodegradable polymer brace that temporarily reduces shank length and consequently, increases its stiffness during implantation, therefore enabling access to deeper brain regions while preserving a low original cross-sectional area of the shanks. The resulting mechanical properties of braced shanks were evaluated at the benchtop. Arrays were then implemented in vivo in freely moving rats, achieving both acute and chronic recordings from the pyramidal cells in the cornu ammonis (CA) 1 and CA3 regions of the hippocampus which are responsible for memory encoding. This work demonstrated the potential for minimally invasive polymer-based neural probe arrays for multi-region recording in deep brain structures.

Fabrication and characterization of zinc oxide piezoelectric MEMS resonator

Micro electromechanical system resonators (MEMS) are being explored to fulfil the demands of speedy wireless communication circuits, which may be utilized as oscillators and/or filters in radio transceivers. Micro resonators of radio frequency range are involved in variety of commercial applications as a replacement of traditional bulky devices due to their small size, high quality factor and most importantly CMOS compatibility. In this work, the design and fabrication of laterally vibrating contour mode MEMS resonator of global system for mobile communication range frequency is presented. Zinc oxide (ZnO), a green piezoelectric material has been used. The ZnO films can also be deposited at low temperature thus reduces thermal budget. An excellent biocompatible/biodegradable property of ZnO may also be useful in resonators used as the detector for mass/pressure sensing for medical applications. The performance of fabricated MEMS resonator is validated by numerical simulations and experimental electrical characterization. The results show that the resonator may be deployed for radio frequency communication. The process to fabricate the resonator has been developed and the devices have been fabricated by surface micromachining techniques on silicon wafer using two electron beam, two optical lithography processes and simple and cost-effective wet etching method used for ZnO etching over costly DRIE process.

Fabrication of surface micromachined molybdenum cantilever beams for PWM MEMS pressure sensor and issues that affect yield

This paper illustrates the methodology adopted for the molybdenum cantilever beam fabrication and the issues faced in the successful realization of such a beam which would be essential component of the PWM based MEMS pressure sensor. The authors in this work have initially fabricated the MEMS mechanical switch with molybdenum cantilever beam using surface micromachining technique. The molybdenum beam switch has been successfully implemented with the proposed fabrication process. However, the yield is poor. The issue regarding the poor yield has been discussed and methods to overcome the same for the enhancement of yield have been presented.

Photomechanical and Chemomechanical Actuation Behavior of Graphene-Poly(dimethylsiloxane)/Gold Bilayer Tube for Multimode Soft Grippers and Volatile Organic Compounds Detection Applications.

Graphene polymers-based soft actuators driven by infrared (IR) light have attracted wide attention recently. However, the scientific fraternity is striving hard in unraveling the area of actuators that could be triggered by IR light along with chemicals. The fabricating methodology of multiresponsive soft actuators based on graphene nanoplatelets (GNPs)-poly(dimethylsiloxane) (PDMS) nanocomposite/gold bilayers, ensuring large, fast, and reversible response, has been illustrated. The actuators display a novel dual-mode operation as photomechanical and chemomechanical actuation. The actuators are realized by depositing a thin film (100 nm) of gold on GNP-PDMS nanocomposite films resulting tubular structure on account of thermal residual stress. The actuation response of this structure upon its exposure to IR light and chemicals was measured in terms of percentage opening and degree of unscroll, respectively. The three-dimensional tubular structure is transformed into a two-dimensional sheet within 8 s under IR light irradiation. The same structures were also tested in various organic solvents like methanol, ethanol, acetone, isopropyl alcohol, and aldehydes, but the actuation has been observed only in acetone and aldehydes. This tubular actuator unscrolls completely and then scrolls in opposite direction along with tube axis shift through 90° during its exposure to acetone (liquid/vapors) and aldehydes. Few applications of these actuators, such as multimode soft grippers for on-demand capture/release of objects (with weight 1.2 times the actuator's own weight) and volatile organic compounds detection module, have been demonstrated. The combination of surface micromachining techniques of microelectromechanical systems process with this smart material may find applications in drug-delivery systems with precise control, soft robotics, and noninvasive diagnosis of diabetes and breast/lung cancers.

A resonant cantilever based particle sensor with particle-size selection function

This paper reports on a novel resonant-gravimetric micro-cantilever based particle sensor for detecting particles (e.g. PM2.5) in air. A row of micro-pillars with desired separation-distance are integrated in a micro-channel that is embedded in the cantilever as a filter to select the particles of desired size. When particles containing air are pumped into the micro-channel, the particles with desired diameters are trapped by the micro-pillars near the free-end of the cantilever, which results in a detectable resonant frequency shift of the micro-cantilever. After detection the sensor can be recovered by reversing the direction of the air flow to blow off the trapped particles and the sensor is ready for the next detection. By tuning the spacing between the barrier bars, the diameters of the trapped particles can be customized for specific detection applications. The complicated structure of the resonant sensor is fabricated by using a novel IC-foundry compatible single-sided surface micromachining technique, with single-side-polished (1 1 1) silicon wafers on a low-cost non-SOI substrate. The sensor prototype has experimentally exhibited excellent real-time detection performance to standard polystyrene micro-spheres, with the resolution of the single particle being distinguishable. The sensor is promising in applications of air pollution monitoring and analysis.

Performance Characterization of Infrared Detectors Based on Polymorphous Silicon‐Germanium (pm‐SixGe1−x:H) Thin Films Deposited at Low Temperature

In this work, the fabrication of infrared detectors (uncooled microbolometers) using surface micromachining techniques is presented. The thermo‐sensing film used in the devices is polymorphous silicon‐germanium (pm‐SixGe1−x:H) produced by low frequency plasma‐enhanced chemical vapor deposition (PECVD) at low temperature (200 °C). Polymorphous semiconductors basically are amorphous semiconductors with embedded nanocrystals (of diameter of about 2–5 nm), which are formed during the film deposition. The presence of nanocrystals impacts on the properties of the material by reducing the density of states (defects) and improving the stability of the films. For infrared detectors those materials present important properties such as high temperature coefficient of resistance (TCR = −4.7% K−1), long‐term stability, low deposition temperature, and silicon CMOS compatibility. Test structures with size of 50 × 50 μm2 and different thermal isolation designs are characterized under IR radiation (0.7–20 μm) in a frequency range of 5–100 Hz. From voltage responsivity and noise measurements, the specific detectivity is calculated achieving values of 1 × 108 cm Hz1/2 W−1 and thermal response time of 8–9 ms under 150 nA bias current. The above characteristics make those devices very suitable for the development of infrared focal plane arrays (IRFPAs).

Acoustical Streaming in Microfluidic CMUT Integrated Chip Controls the Biochemical Interaction Rate

Acoustical fluid mixing and streaming in microfluidic chips enhance the detection and fluid routeing capabilities in the lab-on-chip devices. Capacitive micromachined ultrasound transducers (CMUT) are easy to integrate into a closely packed environment, and they can be simultaneously used as integrated sensors and micropumps/mixers. In this paper, particular focus is given to examininge the impact of the acoustical fluid mixing to the kinetics of biochemical interaction. CMUT interdigital transducers for 10-MHz operation in water were designed and fabricated using the surface micromachining technique. Devices use Scholte type waves for biochemical detection and acoustical streaming. They also have the ability to control the directionality of acoustical streaming by +/−90° phase shift. The impact of acoustical streaming to the liquid diffusion kinetics in the microchannel and to the kinetics of adsorption of the bovine serum albumin (BSA) to the gold surface was investigated experimentally. For microfluidic experiments, CMUTs were assembled with 100 $\mu \text{m}$ deep microchannels. It was determined that acoustical streaming can improve the diffusion rate through the microchannel. Also, it was shown that BSA adsorption rate can be controlled by changing the phase shift during excitation of the Sholte type waves. [2016–0224]

Graphene-polydimethylsiloxane/chromium bilayer-based flexible, reversible, and large bendable photomechanical actuators

We demonstrate the fabrication of highly versatile photomechanical actuators based on graphene-polymer/metal bilayers that offers fast, low-cost fabrication, large deflection, reversible actuation under zero applied pre-strain, and wavelength-selective response. The photomechanical actuator consists of a graphene nanoplatelet (GNP)-polydimethylsiloxane (PDMS) nanocomposite with a thin chromium metal coating of 35 nm thickness on the backside of the structure. The photomechanical response of the GNP-PDMS/Cr photomechanical actuator was measured by recording the variation of the bending angle upon infrared (IR) light illumination. The bending in the bilayer actuator is caused by the generation of thermal stress due to the large mismatch (the ratio being 1/20) of the thermal expansion coefficient between the two layers as a result of IR absorption by GNPs and a subsequent increase in the local temperature. The maximum bending angle was found to be about 40 degrees with a corresponding large deflection value of about 6–7 mm within 6 s for IR illumination with an intensity of 550 mW cm−2. The corresponding actuation response and relaxation times were about 1 and 3 s, respectively. The GNP-PDMS/Cr bilayer combination when integrated with the standard surface micromachining technique of micro-electromechanical system fabrication can find useful applications in the realization of micro soft-robotics, controlled drug delivery, and light-driven micro switches i.e. micro-optomechanical systems.

Practical CMUT Fabrication With a Nitride-to-Oxide-Based Wafer Bonding Process

The introduction of wafer-bonding technique to capacitive micromachined ultrasonic transducer (CMUT) fabrication offered advantages over the surface micromachining technique, such as simplified fabrication, better membrane uniformity, and increased active area. The conventional wafer-bonding CMUT process employs silicon-on-insulator (SOI) wafers to produce the vibrating membrane layer. However, the use of SOI wafers can lead to poor membrane thickness uniformity despite the high cost. Furthermore, an additional local-oxidation (LOCOS) process should be used for SOI-based wafer bonding process to improve breakdown voltage and reduce parasitic capacitance. This paper reports a nitride-to-oxide bonding process for CMUT fabrication, designed to achieve similar results as the LOCOS-added process reported by Park et al. , but without the need for SOIs and fabrication complexity. A fully functional CMUT designed for collapse-mode operation was fabricated and an immersion center frequency was measured to be 4.2 MHz with a 90% bandwidth. [2016-0210]

Low power consumption solid electrochemical-type micro CO2 gas sensor

Micro carbon dioxide gas sensor with low power consumption and high selectivity was fabricated based on micro-heater and electrochemical operation method. Li3PO4 thick film for solid electrolyte and Li2CO3 thick film for sensing material were deposited successively using screen printing technique on Si substrate in the form of slurry. In structure of micro-heater, the resistances of the two semi-circled Pt heaters are connected to the spreader for thermal uniformity. Based on the above design, a low power consumption carbon dioxide gas sensor was fabricated using a CMOS compatible MEMS process. Bridge type micro-heater based on Si substrate was fabricated by surface micromachining technique. Micro gas sensor showed a value of about 50.5mV/decade for air based carbon dioxide gas with 59mW power consumption.

Fabrication process induced changes in scattering parameters of meander type RFMEMS shunt switch

This paper reports about the effect of fabrication process induced changes on scattering parameters of RF MEMS switch structure with meander geometry for 18–40 GHz (Ka-band) application. The designed structure showed a return loss better than 15 dB with a maximum isolation of 43 dB at 35 GHz. From the parametric analysis, both the return loss and isolation parameters are found to be more dependent on the meander width and dielectric thickness compared to the other dimensions. The switch structure is fabricated by surface micromachining technique. The effect of variation of fabricated device dimensions, due to the various processing steps, on the isolation characteristic is also studied. The fabricated structure exhibited an on–off capacitance ratio of ~200:1. The pull-down voltage is found to be 12.5 V. The return loss of the fabricated switch structure is found to be better than 13.5 dB; whereas, the maximum isolation (32 dB) is observed at 33 GHz. The shift in the resonance is due to the reduction of silicon nitride layer thickness during sacrificial layer removal (to release the switch structure) in diluted HF solution. The measured scattering parameters are found to be matching well with the corresponding simulation data of the fabricated switch dimensions.