Office of Technology Transfer – University of Michigan

Assembly Processes for Three-Dimensional Microstructures

Technology #6985

High-performance Micro Electromechanical System (MEMS) sensors and actuators have been commercialized in a variety of applications including motion sensing, wireless communication, energy harvesting, and healthcare. Micro assembly processes are often employed for creating micro sensors and actuators, and they can create more complex micro devices than single-piece, or monolithic, fabrication processes. Limitations in micro assembly processes exist such as 1) low manufacturing throughput; 2) alignment accuracy that prohibits high-performance, capacitive sensors; and 3) large variation in the manufacturing process, which results in large capacitance variations across devices as well as poor uniformity in the electrodes’ capacitances within a device. These limitations prevent many high-performance MEMS sensors and actuators from being manufactured, e.g., a high-performance micro shell rate-integrating gyroscope (RIG).

Manufacturing Process for High-Performance MEMS Devices

A manufacturing process was developed that allows the construction of MEMS with performance that was previously unachievable in practice. The manufacturing process allows highly accurate leveling of a micro shell to a substrate and large controllable gaps between a resonator’s rim and the bottom of the substrate. This results in higher device resolution and stability. The process also achieves highly uniform and narrow (<1 μm) gap sizes between a micro shell and surrounding electrodes, which results in improved readout and actuation capacitances. Finally, a method for improving the alignment of a micro shell resonator achieves uniform sensing and actuation capacitances. A prototype high-performance gyroscope has been manufactured using this process. This manufacturing process has applications in the motion sensing, wireless communication, energy harvesting, and healthcare industries.

Applications

  • Ultra-high performance MEMS sensors and actuators
  • Wireless communication, energy harvesting, and healthcare
  • Inertial Measurement Units
  • Guidance Systems

Advantages

  • Accurate, high-throughput manufacturing
  • Improved resolution and stability
  • Improved, uniform readout and actuation capacitances