A new method for 3D printing MEMS sensors has been developed by researchers at the KTH Royal Institute of Technology. The research has been published in the Nature Microsystems & Nanoengineering journal.
The method aims to reduce costs of MEMS (microelectromechanical systems) for lower production volumes, and the research paper highlights how the researchers have been focusing on one type of sensor in particular; accelerometers.
Costly
While MEMS are relatively cost-effective when produced at industrial scales for common items such as smartphones, the development and manufacturing costs associated with producing MEMS tend to be a lot higher when manufacturing for smaller production runs. Many high tech products such as robots and even certain aircraft are not built in sufficient numbers to benefit from the cost savings associated with full-scale mass production.
Design engineers can often find themselves using suboptimal off-the-shelf MEMS devices in order to realize their designs, or else face huge capital expenditure to obtain custom solutions.
“The new capabilities offered by 3D-printed MEMS could result in a new paradigm in MEMS and sensor manufacturing,” said Frank Niklaus, researcher at KTH Royal Institute of Technology.
“Scalability isn’t just an advantage in MEMS production, it’s a necessity. This method would enable fabrication of many kinds of new, customized devices.”
The Process
The sensors are printed using a two-photon polymerization process capable of printing high resolution objects just a few hundred nanometers in size. This creates the main body of the sensor, but it still requires further steps to make it function as a sensor.
To achieve this they use a process called shadow-masking. On the printed body a T-shaped structure is added which functions as an umbrella, shielding certain parts of the printed body when the metal is deposited in the next stage. After the metal is deposited, it forms a metal layer which is electrically isolated from the rest of the body. The graphic below explains it much better.
By using this combination of two-photon polymerization printing combined with the shadow masking, they are able to produce dozens of MEMS sensors in just a few hours. While that doesn’t sound like a lot, the cost of prototyping these things is reduced significantly. Smaller production runs are now economically viable also.
“This is something that has not been possible until now, because the start-up costs for manufacturing a MEMS product using conventional semiconductor technology are on the order of hundreds of thousands of dollars and the lead times are several months or more,” said Niklaus.
“The new capabilities offered by 3D-printed MEMS could result in a new paradigm in MEMS and sensor manufacturing.”
The research paper, titled “Micro 3D printing of a functional MEMS accelerometer” can be found in the Nature Microsystems & Nanoengineering journal, which can be found at this link.