MEMS Research Papers - Academia.edu (original) (raw)

Early warning systems are becoming one of the main pillars of disaster prevention in natural hazards especially where mitigation strategies are not realizable. Therefore, the call for multi-hazard early warning systems and improvement of... more

Early warning systems are becoming one of the main pillars of disaster prevention in natural hazards
especially where mitigation strategies are not realizable. Therefore, the call for multi-hazard early warning systems and improvement of monitoring of natural hazards is steadily growing. However, data gathering (generation) through sensor integration as well as system independent supply of information from early warning networks are of particular challenge. Because very complex information and warning chains have to be served for, standardization and interoperability plays an important role for all organizations and infrastructures being involved. The SLEWS project investigates the complete information chain, starting from data gathering using wireless sensor networks via information processing and analysis to information retrieval. This is demonstrated for landslides and mass movements. The proposed approach adds especially to the funding target of mobile, cost-reduced and easy deployable measurement systems, as well as the modern information systems under consideration of interoperability and service orientated architecture concepts. The proposed wireless network provides the basis for applying further techniques like sensor fusion, identification of malfunctions or errors. The obtained geodata is processed according to the requirements of particular users and can be provided for use in a local or regional as well as global information structure. Interfaces will be created, which make a mobile and flexible adaptation or integration of geodata possible. Thus, it is ensured that the early warning system reaches the spectrum of potential users and provides a maximum flexibility.

The micro-accelerometers are devices used to measure acceleration. They are implemented in applications such as tilt-control in spacecraft, inertial navigation, oil exploration, etc. These applications require high operating frequency and... more

The micro-accelerometers are devices used to measure acceleration. They are implemented in applications such as tilt-control in spacecraft, inertial navigation, oil exploration, etc. These applications require high operating frequency and displacement sensitivity. But getting both high parameter values at the same time is difficult, because there are physical relationships, for each one, where the mass is involved. When the mass is reduced, the operating frequency is high, but the displacement sensitivity decreases and vice versa. The implementation of Displacement-amplifying Compliant Mechanism (DaCM) supports to this dependence decreases. In this paper the displacement sensitivity and operation frequency of a Conventional Capacitive Accelerometer are shown (CCA). A Capacitive Accelerometer with Extended Beams (CAEB) is also presented, which improves displacement sensitivity compared with CCA, and finally the implementation of DACM´s in the aforementioned devices was also carried out. All analyzed cases were developed considering the in-plane mode. The Matlab code used to calculate displacement sensitivity and operating frequency relationship is given in Appendix A. Keyword: Accelerometer Displacement Frequency MEMS Sensitivity

Functional liquid-crystalline elastomers (FULCE) are a new class of smart materials that show a reversible change of shape when heated or irradiated with UV light. These materials have a high potential for use as actuators with large... more

Functional liquid-crystalline elastomers (FULCE) are a new class of smart materials that show a reversible change of shape when heated or irradiated with UV light. These materials have a high potential for use as actuators with large deformation and small forces in micromechanical systems. Within an EU project, we investigate the possibility
of integration of the materials in MEMS. We did show compatibility with standard MEMS technologies, and tested a method for hybrid assembly of FULCEs on silicon and glass substrates without the use of adhesives. All these processes were found suitable for application.

Upcoming book on the materials and their failures in Microelectromechanical systems and Nanoelectromechanical Systems, edited by Atul Tiwari and Baldev Raj (Director NIAS, India) and being published by Wiley-Scrivener press, USA .

There is considerable interest in using interdigitated arrays as sensors in both aqueous and non-aqueous fluids. However, highly resistive non-aqueous fluids present substantially different design constraints than conductive aqueous and... more

There is considerable interest in using interdigitated arrays as sensors in both aqueous and non-aqueous fluids. However, highly resistive non-aqueous fluids present substantially different design constraints than conductive aqueous and polar non-aqueous solutions. Analytical equations for the performance of planar interdigitated devices in highly resistive non-aqueous industrial fluids were developed and used to design a series of prototypes. Theoretical expressions describing the cell constant, bulk and interfacial resistances and capacitances of interdigitated sensors are reported, leading to conclusions on appropriate empirical and modeling evaluation methods for design and optimization of interdigitated sensors for testing in highly resistive solutions. Electrochemical impedance spectroscopy (EIS) was used to compare prototype performance to analytical equations. In addition, the prototype devices were compared to solid parallel plate electrodes, which are typically used for EI...

several survey reports on vehicle accident say that, mostly accidents are happening due to Drunk and driving, driver’s drowsiness and, over speed. Unnecessary sudden parking of vehicles on highways at night time is another factor .If... more

several survey reports on vehicle accident say that, mostly accidents are happening due to Drunk and driving, driver’s drowsiness and, over speed. Unnecessary sudden parking of vehicles on highways at night time is another factor .If these mistakes are corrected accidents can be reduced to some extent. If accidents occurred, immediate first aid and treatment is necessary to save life. But if there is no neighbor the case may be severe. Keeping all these in mind a new system is proposed which can perform the necessary steps to prevent accident and incase if accident happened system will inform the owner and ambulance about this accident by tracking location using GPS and send text message using GSM. The designed system involves in two sections1. Monitoring 2.control. These two are two sequence of actions. In monitoring phase it detects alcohol consumption, steering wheel grip, engine Temperature measurement, accident detection and distance between front and corresponding vehicle .In controlling phase system responds automatically for the above abnormalities and controls the engine. system software is designed using “ RT kernel” and “Keil Micro vision 5” to be worked on the target board of LPC2148. This system makes vehicles as highly secured.

Abstract— Experimental results leading to breakdown voltage (BDV) measurements conducted with blade-blade, hemisphere-hemisphere and needle-plane electrode configuration in air at STP have been reported in this paper. The applied voltage... more

PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement... more

PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement of performance and flexibility. Modelsim as simulation platform and VHDL used to translate, integrate and implement the logic circuit in FPGA. Xilinx's Spartan kit for implementation-testing and VB has been used for GUI development. Salient merits of the design include cost-effectiveness, miniaturization, user-friendliness, simplicity, along with lower power consumption, smaller scan time and higher speed. Various functionalities and applications like typical PLC and industrial alarm annunciator have been developed and successfully tested. Results of simulation, design and implementation have been reported.

Here we report on bulk Si–Al–O–C ceramics produced by pyrolysis of commercial poly(methylsilsesquioxane) precursors. Prior to the pyrolysis the precursors were cross-linked with a catalyst, or modified by the sol-gel-technique with an... more

Here we report on bulk Si–Al–O–C ceramics produced by pyrolysis of commercial poly(methylsilsesquioxane) precursors. Prior to the pyrolysis the precursors were cross-linked with a catalyst, or modified by the sol-gel-technique with an Al-containing alkoxide compound, namely alumatrane. This particular procedure yields amorphous ceramics with various compositions (Si1.00O1.60C0.80, Si1.00Al0.04O1.70C0.48, Si1.00Al0.07O1.80C0.49, and Si1.00Al0.11O1.90C0.49) after thermal decomposition at 1100 °C in Ar depending on the amount of Al-alkoxide used in the polymer reaction synthesis. The as-produced ceramics are amorphous and remain so up to 1300 °C. Phase separation accompanied by densification (1300–1500 °C) and formation of mullite at T > 1600 °C are the stages during heat-treatment. Bulk SiAlOC ceramics are characterized in terms of microstructure and crystallization in the temperature regime ranging from 1100 to 1700 °C. Aluminum-free SiOC forms SiC along with cracking of the bulk compacts. In contrast, the presence of Al in the SiOC matrix forms SiC and mullite and prevents micro cracking at elevated temperatures due to transient viscous sintering. The nano-crystals formed are embedded in an amorphous Si(Al)OC matrix in both cases. Potential application of polysiloxane derived SiOC ceramic in the field of ceramic micro electro mechanical systems (MEMS) is reported.

We report an on-board microfluidic pump driven by magnetic stir bar that can be integrated into the micro-total-analysis systems (µTAS) without micro-to-macro connection. Rotational magnetic field causes the spinning of the magnetic stir... more

We report an on-board microfluidic pump driven by magnetic stir bar that can be integrated into the micro-total-analysis systems (µTAS) without micro-to-macro connection. Rotational magnetic field causes the spinning of the magnetic stir bar that generates centrifugal force to propel the flow. The pump controls both the flow rate and flow direction when positioned on specific locations of a magnetic stir plate set at varied spin velocities.

We have developed a micro-scale chip-based pH sensing system, which can effectively measure the changes in pH ranging from 1 to 4 and 10 to 12. This method relies on fringing field capacitive measurements. A change in pH of the medium... more

We have developed a micro-scale chip-based pH sensing system, which can effectively measure the changes in pH ranging from 1 to 4 and 10 to 12. This method relies on fringing field capacitive measurements. A change in pH of the medium results in a permittivity change for the fringing electric field, which in turn affects the capacitance values. Capacitance changes are then converted to resonant frequency shifts via a readout circuit. This technique provides high sensitivity, low hysteresis, and low noise as well as low fabrication cost. Very importantly, the device and the corresponding measurement circuitry have the potential to be integrated in an electronic pill for continuous non-invasive measurement within the body.

Today most of the countries facing many environmental problems out of which water pollution are extremely hazards and world's most of the countries facing enormous challenges to solve this. Water pollution due to Heavy Metal Ions (HMIs)... more

Today most of the countries facing many environmental problems out of which water pollution are extremely hazards and world's most of the countries facing enormous challenges to solve this. Water pollution due to Heavy Metal Ions (HMIs) is a global issue which requires proper attention to maintain the water quality demands. A portable system made of MEMS sensors capable of detecting multiple analytes simultaneously is highly demanded. The HMI detection in vapour phase can be a solution for laboratory based detection, but for the field instrument using MEMS the temperature cannot be raised beyond certain limit. Hence, the microfluidic detection is the only option which required high sensitivity. Accordingly, our main objective is to develop a microfluidic platform that can be used for sensing HMIs using a capacitive microcantilever beam fabricated by using MEMS technology. The proposed system is divided into two parts; the first one includes microfluidic chamber or tub and polydimethylsiloxane (PDMS) based microfluidic channel for handling water and second one uses the array of microcantilever beams surface modified with different protein for selective detection of HMIs. In this work, we try to investigate the cantilever based capacitive sensor for different pressure due to HMIs and sensitivity enhancement. Sensitivity optimization is very much essential and it is improved by using different shape, stress concentration region (SCR) and changing the dimension of microcantilever for HMI detection in water environment. It is found that in case of rectangular beam with SCR improves deflection up to 33% and in case of triangular beam this improvement is up to 73%.

The Internet of Things is an intelligent network, which concatenates all things to the Internet for the purpose of interchange information and communicating via the information sensing devices in conformity with agreed protocols. We could... more

The Internet of Things is an intelligent network, which concatenates all things to the Internet for the purpose of interchange information and communicating via the information sensing devices in conformity with agreed protocols. We could also elucidate the IoT as the next stage in the Internet as some do, whereby things and objects with sensors and actuators are concatenated to the Internet so they can accumulate, send and get data, leading to intelligent solutions and in some cases also act upon data. In this paper, we survey state-of-the-art methods, internet of things (IoT) and its enabling technology in this new emerging area. Because, in the IoT physical objects may also make conclusion about the amassed, processed, and interchange information, as well as take expeditions to control the physical objects and the environment in which they are embedded. The capacities that enable the physical objects to get involved with in the IoT are ordinarily composed of an assemblage of various types of advanced technologies including software, actuators, sensors, and electronics. The IoT assents actuators and computer interfaced sensors to encourage to novel products and services by minimizing costs, increase efficiency, and enhancing the user-friendliness of existing systems. These capacities are either concatenate to or integrated into traditional products and systems. In the end, we will thoroughly analyze the technical details about the IoT enabling technology.

Smart dust is a tiny dust size device with extraordinary capabilities. Smart dust combines sensing, computing, wireless communication capabilities and autonomous power supply within volume of only few millimeters and that too at low cost.... more

Smart dust is a tiny dust size device with extraordinary capabilities. Smart dust combines sensing, computing, wireless communication capabilities and autonomous power supply within volume of only few millimeters and that too at low cost. These devices are proposed to be so small and light in weight that they can remain suspended in the environment like an ordinary dust particle. These properties of Smart Dust will render it useful in monitoring real world phenomenon without disturbing the original process to an observable extends. Presently the achievable size of Smart Dust is about 5mm cube, but we hope that it will eventually be as small as pack of dust. Individual sensors of smart dust are often referred to as motes because of their small size. These devices are also known as MEMS, which stands for micro electro-mechanical sensors.

This paper describes the design and fabrication of planar micro-coil on printed-circuit board (PCB)for magnetic MEMS actuator. A simple and cost effective technique for the fabrication of planar micro-coil is presented. The design and... more

This paper describes the design and fabrication of planar micro-coil on printed-circuit board (PCB)for magnetic MEMS actuator. A simple and cost effective technique for the fabrication of planar micro-coil is presented. The design and analysis process have been carried out by using COMSOL Multiphysics 4.2. Three different coil dimensions such as width/space= 150μm/100μm; 100μm/100μm and 50μm/100μm, have been analyzed in order to find the optimum coil geometry. The results showed that the coil with dimension of width/space of 50μm/100μm produced the highest magnetic flux density of max 0.0068 T. The optimized design of the planar micro-coil can be used as a reference for the future fabrication of magnetic MEMS actuator.

A brief review on the use of acoustic waves in designing MEMS based resonator is described in this paper. Acoustic devices can be further classified into two basic types – Surface acoustic wave (SAW) and Bulk acoustic wave (BAW)... more

A brief review on the use of acoustic
waves in designing MEMS based resonator is
described in this paper. Acoustic devices can be
further classified into two basic types – Surface
acoustic wave (SAW) and Bulk acoustic wave
(BAW) devices. A BAW resonator is modeled
and simulated using COMSOL Multiphysics 4.3.
In this model variation in thickness and
piezoelectric material is the prime focus for
studying the basic variation in series resonance
and surface deformation of the device.

Over the past few decades the increased level of public awareness concerning healthcare, physical activities, safety and environmental sensing has created an emerging need for smart sensor technologies and monitoring devices able to... more

Over the past few decades the increased level of public awareness concerning healthcare, physical activities, safety and environmental sensing has created an emerging need for smart sensor technologies and monitoring devices able to sense, classify, and provide feedbacks to users’ health status and physical activities, as well as to evaluate environmental and safety conditions in a pervasive, accurate and reliable fashion. Monitoring and precisely quantifying users’ physical activity with inertial measurement unit-based devices, for instance, has also proven to be important in health management of patients affected by chronic diseases, e.g., Parkinson’s disease, many of which are becoming highly prevalent in Italy and in the Western world. This review paper will focus on MEMS sensor technologies developed in Italy in the last three years describing research achievements for healthcare and physical activity, safety and environmental sensing, in addition to smart systems integration. Innovative and smart integrated solutions for sensing devices, pursued and implemented in Italian research centres, will be highlighted, together with specific applications of such technologies. Finally, the paper will depict the future perspective of sensor technologies and corresponding exploitation opportunities, again with a specific focus on Italy.