Faculty Development Program on Micro-Electro-Mechanical Systems (MEMS Report MEMS sensors have been dominating the consumer products such as mobile phones, music players and other portable devices. With India planning for Smart Cities, sensors and their design would be very important for data acquisition and monitoring. Designing sensors has become ubiquitous with any small electronic gadget. IntelliSuite is the industry-leading tool set for MEMS layout design, advanced process simulation, FEA, parametric analysis, system simulation, packaging analysis.
About GTU Gujarat Technological University (International Innovative University), commonly referred as GTU, is a state wide institution affiliating many engineering, pharmacy, and management colleges and varsities across the western Indian districts of Gujarat. GTU has been working jointly with industries through GTU Innovation Sankuls (Every college is a member of the Sankuls in its area). It has been working with the students through the GTU Innovation Clubs, Open Source Technology Clubs, IPR, CiC3, and S4 Extension Centers etc. To foster innovative ideas and to explore new horizons in the field of Engineering, Community Innovation & Co-Creation Centre organizes various workshops, hackathon s, challenges and Faculty Development Programs. The Programme Community Innovation and Co-Creation Centre (CiC3) has announced Faculty Development Program on Design and Simulation of MEMS Sensor (Micromirror, Accelerometer & Microphone). MEMS sensors have been dominating the consumer products such as mobile phones, music players and other portable devices. With India planning for Smart Cities, sensors and their design would be very important for data acquisition and monitoring. Designing sensors has become ubiquitous with any small electronic gadget. IntelliSuite is the industry-leading tool set for MEMS layout design, advanced process simulation, FEA, parametric analysis, system simulation, packaging analysis. With users in over 30 countries, IntelliSense is the largest MEMS software vendor with its own in-house fabrication facility. IntelliSense also provides a global One Stop MEMS Solution for universities, blue-chip companies and start-ups with its custom design, consulting and fabrication services. The 3 day workshop was for students and faculty in the departments of Electronics and Communication Engineering, Instrumentation Engineering, Telecommunication Engineering, Mechanical Engineering, Electrical and Electronics Engineering, Biomedical Engineering and allied branches. 1
Introduction Microelectromechanical systems (MEMS) integrate mechanical and electrical components and have feature sizes ranging from micrometers to millimeters. They may be fabricated using methods similar to those used to construct integrated circuits and they have the potential of providing significant cost advantages when batch fabricated. Their size also makes it possible to integrate them into a wide range of systems. Feature sizes may be made with size on the order of the wavelength of light, thus making them attractive for many optical applications. Microsensors (e.g., accelerometers for automobile crash detection and pressure sensors for biomedical applications) and micro actuators (e.g., for moving arrays of micro mirrors in projection systems) are examples of commercial applications of MEMS. Microelectromechanical systems (MEMS) are micrometer-scale devices that integrate electrical and mechanical elements. They have been used in diverse applications, from display technologies to sensor systems to optical networks. MEMS are attractive for many applications because of their small size and weight, which allow systems to be miniaturized. 2 The sensors in MEMS gather information from the environment through measuring mechanical, thermal, biological, chemical, optical, and magnetic phenomena. The
electronics then process the information derived from the sensors and through some decision making capability direct the actuators to respond by moving, positioning, regulating, pumping, and filtering, thereby controlling the environment for some desired outcome or purpose. The advantages of semiconductor IC manufacturing such as low cost mass production, reliability are also integral to MEMS devices. The size of MEMS sub-components is in the range of 1 to 100 micrometers and the size of MEMS device itself measure in the range of 20 micrometers to a millimeter. The event was commenced with the welcome note by Dr. Apurv Raval Deputy director GTU. The dignitaries of the FDP were included Dr. Geetha Prakash, Mr. Sripadaraja K.. Mr. Mitesh Solanki, Ms. Tosha Shukla, Ms. Rutika Ghariya Assistant Professor Gujarat Technological University. The workshop was started right after the inaugural address by Dr. Apurv Raval, Deputy Director of Gujarat Technological University. All the dignitaries expressed their views while explaining the importance of the FDP and MEMS sensor. Day 1, Dr. Geetha Prakash explained about importance of Micro Electro-Mechanical Systems, why need MEMS sensor, Application of MEMS sensor in different domain: Automotive domain, Consumer domain, Industrial domain, Military, Biomedical, Some of the advantages of MEMS devices. 3
This vision of MEMS whereby microsensors, microactuators and microelectronics and other technologies, can be integrated onto a single microchip is expected to be one of the most important technological breakthroughs of the future. This will enable the development of smart products by augmenting the computational ability of microelectronics with the perception and control capabilities of microsensors and microactuators. Microelectronic integrated circuits can be thought of as the "brains" of a system and MEMS augments this decision-making capability with "eyes" and "arms", to allow microsystems to sense and control the environment. Sensors gather information from the environment through measuring mechanical, thermal, biological, chemical, optical, and magnetic phenomena. 4 The electronics then process the information derived from the sensors and through some decision making capability direct the actuators to respond by moving,
positioning, regulating, pumping, and filtering, thereby controlling the environment for some desired outcome or purpose. Furthermore, because MEMS devices are manufactured using batch fabrication techniques, similar to ICs, unprecedented levels of functionality, reliability, and sophistication can be placed on a small silicon chip at a relatively low cost. MEMS technology is extremely diverse and fertile, both in its expected application areas, as well as in how the devices are designed and manufactured. Already, MEMS is revolutionizing many product categories by enabling complete systems-on-a-chip to be realized. Mr. Sripadaraja K explained about design of a capacitive accelerometer from initial system-level design exploration, through fabrication processing and device-level analysis. He also explained analyze the accelerometer, developed and discuss the benefits of IntelliSuite when it comes to MEMS-based accelerometer design. Begin the design exploration in SYNPLE, the schematic-based simulator. Analyses can be performed very quickly in this tool, making it ideal for the initial design stages. From the mask layout automatically generate a 3D meshed model to be used for finite element analysis. Day 2, Dr. Geetha Prakash explained about importance of Optical Sensors. Optics and photonics are among these research fields impacted by MEMS techniques. Optical MEMS has created a new fabrication paradigm for optical devices and systems. 5
These micro optical devices and systems are inherently suited for cost effective wafer scale manufacturing as the processes are derived from the semiconductor industry. The ability to steer or direct light is one of the key requirements in optical MEMS. The displays were the main driving force for the development of micromirror arrays. Portable digital displays are common places and head mount displays are now commercially available. Mr. Sripadaraja K explained about design and fabrication technology like surface micromachining, bulk micromachining, and molding, Micromodel Extraction, Simulation in SYNPLE and Micro Mirror array Simulation and Visualization. 6
He also explained on-chip actuation of microsystems has been a particularly challenging aspect of MEMS development. Common macro-level actuation approaches, such as hydraulics, pneumatics, electric motors, internal combustion engines and turbines, are either too difficult to fabricate at the micro level or do not work well at that scale. Electrostatic attraction is one approach that has been widely used for actuation of microsystems. While electrostatic actuation is suitable for many applications, some systems require either lower voltages or higher output forces. Electrostatic and thermal actuation approaches are described in more detail. Day 3, Dr. Geetha Prakash explained about importance of Optical Sensor microphone. The application of MEMS (Micro Electro-Mechanical Systems) technology to microphones has led to the development of small microphones with very high performance. MEMS microphones offer high SNR, low power consumption, good sensitivity, and are available in very small packages that are fully compatible with surface mount assembly processes. MEMS microphones exhibit almost no change in performance after reflow soldering and have excellent temperature characteristics. 7
She also explained MEMS microphones use acoustic sensors that are fabricated on semiconductor production lines using silicon wafers and highly automated processes. Layers of different materials are deposited on top of a silicon wafer and then the unwanted material is then etched away, creating a moveable membrane and a fixed backplate over a cavity in the base wafer. The sensor backplate is a stiff perforated structure that allows air to move easily through it, while the membrane is a thin solid structure that flexes in response to the change in air pressure caused by sound waves. Mr. Sripadaraja K explained about design and fabrication process, Process flow sheet in IntelliFab, Material properties, Boundary Conditions, sensitivity and Measurement of capacitance. 8
Valedictory Session Valedictory session of the program was graced by the presence of Dr. Mihir Shah (Professor, LD College of Engineering, Ahmedabad). He took eager interest in the MEMS sensor designed & developed by students and faculty members during the workshop and appreciated their dedication & effort. He also motivated students to keep looking for opportunities where they can utilize their learning and can get chance to implement what is demonstrated during the three days of workshop. Reported By Mitesh Solanki Assistant Professor GTU Sensor Lab, CiC3, GTU 9