What is MEMS technology?

MEMS technology is really cool. However, he is a complete unknown. In this course, you’ll be able to learn about it and see how this type of semiconductor manufacturing technology can create truly tiny mechanical devices that you can’t even imagine can be made.

What is MEMS?

MEMS (MicroElectroMechanical Systems), or microelectromechanical systems, refers to a type of technology for developing microscopic devices with moving parts that take advantage of the same technology used to manufacture chips. This concept also includes SNEMs or nanoelectromechanical systems, also known as micromachines in Japan or MST in Europe.

The idea is to produce mechanical elements that work as a complete system on a larger scale, but in very small dimensions. All of these have applications, in fact, some of them you may have unwittingly used, such as gyroscopes and similar sensors used in many mobile devices. Also automotive industry, biomedicine, electronics etc. It also has applications in the fields. Even small-sized robots could be produced, but the biggest problem was the lack of microenergy sources with high current density, power and capacity to feed them.

MEMS Applications

When it comes to MEMS applications, some stand out:

  • Ink nozzles for printers using piezoelectric or thermal bubble jets.
  • Micromotors or nanomotors.
  • Small watches.
  • Accelerometers for airbag deployment for a wide range of devices from the automotive industry to smartphones.
  • Orientation in many cars, mobile devices, dynamic stability control, etc. MEMS gyroscopes used for
  • Small size silicon pressure sensors.
  • Displays like DMD chips in DLP-based projectors.
  • Fiber optic technologies for communication.
  • Biosensors, new “smart” drugs, analytics, etc. for biomedicine or biotechnology.
  • IMOD consumer electronics applications.
  • Navigation microsystems.
  • Cyborgs.
  • AFM sensors or atomic force microscopy.

Materials that make up MEMS

Advances in the field of semiconductors have opened the door to other similarly created technologies such as MEMS. These elements can be produced from many different materials, though these are the most obvious:

  • Silicone: Since it is a semiconductor material, it is a material frequently used in MEMS devices with electronic components. Most of the MEMS devices produced for the market are based on this material, which has other advantages such as high quality, low cost and not having to change semiconductor factories to create these mechanisms.
  • Polymers: Polymers are another option due to their wide variety of properties and very economical cost. Also, these polymers can be produced in high volumes from a wide variety of materials, unlike silicone, which should be EGS. On the other hand, another advantage of polymers is that MEMS can be created for microfluidic applications such as disposable cartridges for blood tests.
  • Metals: Just as metal interconnects are used in semiconductor chips, metal can be used to make elements in MEMS, which is a great advantage. Metals have better mechanical properties than silicon, so they overcome some of their limitations and are more reliable. Metals that can be used include copper, aluminum, gold, nickel, chromium, titanium, tungsten, silver, platinum, etc.
  • Others: Of course, other materials can be used beyond the above, such as catfish, nitrides and many other compounds. In fact, anything that supports deposition and etching can be used for a MEMS.

How can small elements like MEMS be made?

Physico-chemical techniques are used to fabricate MEMS devices because there are no instruments small enough to be produced at such scales. In other words, they manufacture these tiny mechanisms in the same way, taking advantage of all the developments in the chip industry. And this includes the following stages:

  1. It starts from a rod, which is a surface that can be made of different materials such as silicone.
  2. A layer of silicon oxide may be grown on this rod, or metals or materials other than those mentioned above may be deposited.
  3. Once you have the substrate you want to make MEMS components, you proceed to place them in a photoresin, which is a liquid that will cure to become a solid.
  4. Then comes the photolithography process, in which the rod is exposed to light by passing it through a pattern containing the design you want to create. This causes some parts of the photoresist to be exposed to light and others not.
  5. The rod is ready for the next stages as the exposed and invisible parts change its properties as a photosensitive material.
  6. An etching can then be done using an abrasive agent that removes the exposed (or unexposed) layer of the photoresist, as well as the exposed parts by removing the photoresist from the underlying material.
  7. In this way, structures are created in desired sizes and figures.
  8. These processes can be repeated as needed until the different layers make up the entire system.

Frankly, these points are a very primitive way of explaining it, but they are easy to understand without going into too much technical detail that could lose the reader.