What is MEMS and why use MEMS
A Micro-electromechanical system as the name implies it is a combination of electrical and mechanical components. Most of the electronics or electromechanical devices that we use today is created by the MEMS. Laptops, mobile phones are created by using a nanoscale device. MEMS are widely used in many applications like many sensors are created by the help of MEMS an example of this will be a pressure sensor. In the medical section, MEMS plays a great role most of the biomedical equipment is constructed by using MEMS technology. So in general we can say that in our day to day life we use MEMS technology. The microchip is constructed by using MEMS technology. MEMS can be considered as an evolution of the VLSI (very large scale integration) the IC’s are constructed by using VLSI technology. We can create microdevice by using MEMS technology and the created device can sense, act, process, and communicate. The MEMS device can be considered as the integration of sensors, actuators, mechanical elements, and electronics in a silicon substrate.
How does a MEMS sensor work
The MEMS sensors start its operation with the help of any external force. This force would be applied to the moving structure of the sensor and when this force hits the structure then it would be deflected. This deflection is then measured by some electrical or optical techniques. Then it would calculate the applied external force.
How MEMS are manufactured
MEMS can be considered as a combination of micro-sensors, micro-actuators, micro-structures, and micro-electronics. MEMS has microstructure, mechanical functionality, system control, and electrical signal control. Silicon is used for MEMS manufacturing because they are cheap and easily available, it gives long service and can be reliable for a small device. Other materials such as polymers and metals are used for MEMS manufacturing. There are certain steps to manufacture MEMS. The deposition process in this process thin films of material would be deposited on a substrate. Photolithography (surface micro matching) in this process UV rays are used in a silicon wafer to create MEMS devices. Lithography is another method by this method we can create micro gears and microstructures in this process X-rays are used to create patterns. In this process, a mask would be laid on top of the film. After that etching will be done to create a proper MEMS device.
What is MEMS micro-system
A micro-system consists of sensors, actuators, and an electronic circuit. The sensor would provide the input or information to the system. Then the sensor signal will reach the electronic circuit and then the electrical signal will be sent to the actuator and it would respond to the signal. Some of the microsystem products are micro-gear, micro- motors, micro-turbines, and micro-optical components.
Why do we need to use MEMS sensor and what are its advantages
MEMS sensors are smaller in size so it is better than the conventional type. It has certain advantages like small size, power consumption is decreased, the sensitivity of the sensor is increased, it can be constructed with less cost so mass production can be done. MEMS sensors are less invasive because they are smaller in size.
How MEMS device is better than other device
- Mechanical inertia will be less so the movement of the components will be less
- So it is suitable for precision movements, and for quick actuation
- Because of low mass MEMS device won’t be affected by thermal distortion and mechanical vibration
- Due to smaller size it can be used for biomedical and aerospace applications
- The dimensional stability of this device at high temperature will be good because of its size
- Space consumption will be less
What is a MEMS accelerometer and how does it work
An accelerometer is a device that is used to measure the acceleration. The accelerometer that is created by using the MEMS technology would be small in size and of low cost. This device is also used in airbag sensors. Accelerometers are devices that can measure the acceleration forces. There was an evolution in automotive airbags and it is caused by the MEMS accelerometers. MEMS accelerometers are compact and they provide lower power and better sensing capability. The MEMS accelerometer consists of plates and proof mass these plates will be connected to the reference frame with the help of a mechanical suspension system. There are movable and fixed plates and they are considered as capacitors. If an input is given to this accelerometer the proof mass will be deflected and it will be calculated by the difference in capacitance.
What is optical MEMS
Optical MEMS is a combination of sensors, actuators, and electronics and all of this will be combined by doing micro-fabrication in a silicon substrate. Optical MEMS has made a revolution in optical communication systems. With the help of optical MEMS miniaturization and integration are widely achieved in optical communication systems.
What are MEMS micro sensors
The microsensors which is created by using MEMS is the MEMS micro-sensors. These sensors will be very small and they would be very efficient and reliable. The power consumption of these sensors would below. These sensors would be highly sensitive to input variations. Many sensors are created by using MEMS technology some of them are mechanical sensors, optical sensors, thermal sensors, chemical, and biological sensors. MEMS sensors are used in military operations and in aircraft. Some of the micro-sensors that are created by using MEMS technology is Strain gauges accelerometers, gyroscopes…
We can see MEMS sensors in smartphones, laptops, etc. In a smartphone, we can see a lot of MEMS sensors like accelerometer, gyroscope, pressure sensors. MEMS sensors are also used in aeronautic, automotive, biomedical, biotechnology…
MEMS in future
We can create many micro-devices with the help of MEMS. We can see many changes in space aircraft with the help of MEMS. Small size robots and devices can be created by using MEMS. MEMS can create many changes, in automotive, aeronautics, biomedical, consumer electronics, and in many other fields.
What are the applications of MEMS
- Pressure sensors are created by using MEMS and these sensors are used in medical, industrial and automotive applications
- Accelerometers are used in automotive, avionics and industrial applications
- Gyroscope are used in Automotive and avionics
- RF components are used for switches and a circuit element
- Fiber optics are used for relays and attenuators
- MEMS has a wider range of applications in medical field certain devices like bio-analyzers and microneedles are used for drug delivery, DNA sequencing and chemical analysis
- In IT sector most of the storage devices are created by using MEMS technology
- MEMS are used in optical field like Pill camera
- Biotechnology – many sensors are used that is created by MEMS technology
- In virtual reality systems inertial sensors are used which is made up of MEMS
- MEMS microsensors are used in the biomedical, acoustic wave, chemical inertia, pressure, thermal…
- Defence – Arming sensors, Embedded sensors,…
What are the advantages of MEMS
- Less manufacturing cost
- Smaller size
- Multitasking
- Quick response
- Better sensitivity
- Better accuracy and reliability
- Decrease in the power budget
- The device accuracy and reliability will be improved
- Good scaling properties
What are the disadvantages of MEMS
- Starting cost will be high
- The micro components are costly compared to the macro
- The designing will be very complex
- Better knowledge is required to integrate the MEMS device