Modeling Compliant Mechanism Flexure Hinges for Flapping Wing Nano Air Vehicles

Open Access
Koffler, Peter Alan
Area of Honors:
Mechanical Engineering
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Christopher D. Rahn, Thesis Supervisor
  • Henry Joseph Sommer III, Honors Advisor
  • Flexure Hinge
  • Compliant Mechanism
  • MEMS
  • Nano Air Vehicle
  • FEA
  • Finite Element Analysis
  • Stress
  • SolidWorks
  • Ansys
  • Matlab
The piezoelectrically actuated flapping wing nano air vehicle at the center of this analysis was developed by Dr. Kiron Mateti for a PhD Thesis supervised by Dr. Chris Rahn over the past five years [1]. The design of the Eristalis flapping wing is unique for its single material construction. Small scale assembly procedures common in other nano air vehicles were eliminated by etching the required wing geometry from a single sheet of SUEX epoxy photoresist material. The resulting wing utilizes compliant mechanism flexure hinges instead of more conventional multi-part hinges to transfer loads. The design was tested extensively by Dr. Mateti to measure the thrust produced by flapping for different wing and hinge geometries. However, a common occurance during the wing testing was the failure of the complaint beam hinges. This thesis focuses on determining the stresses in the compliant flexure hinges using both beam theory and ANSYS Finite Element Analysis software. Identical displacement and force loads will be prescribed to hinge models of complexity ranging from 2D beam to 3D solid elements. Both static and dynamic operation of the wing will be considered. The results of various stress analysis techniques will be compared to help future flexure hinge designers model stresses by the simplest means possible while still achieving sufficient accuracy.