Optimized Flexural Hinges for Compliant Micromechanisms

In this work a procedure for the optimal design of flexural hinges to be microfabricated by a lithographic process is proposed. The structural optimization problem is approached by coupling a parametric finite element model to an optimization algorithm. A computer code was developed to generate the mesh at each optimization step accordingly to the values of the design parameters provided by an optimization toolbox. The objective function is the rotation of the mechanism, which must be maximized. The solution is constrained by strength and kinematical requirements. The notch shape is described by spline functions according to an original procedure developed by the authors. Results show that, with respect to the usual design approach, the proposed method permits a significant improvement of the hinge characteristic to be obtained.

[1]  V. P. Jaecklin,et al.  Micromechanical Comb Actuators with Low Driving Voltage , 1992 .

[2]  Nicolae Lobontiu,et al.  Design of symmetric conic-section flexure hinges based on closed-form compliance equations , 2002 .

[3]  Larry L. Howell,et al.  A PARAMETRIC APPROACH TO THE OPTIMIZATION-BASED DESIGN OF COMPLIANT MECHANISMS , 1997 .

[4]  G. K. Ananthasuresh,et al.  Designing compliant mechanisms , 1995 .

[5]  Stephanus Büttgenbach,et al.  A New Micro Pneumatic Actuator for Micromechanical Systems , 2001 .

[6]  LiZhe,et al.  Design of Compliant Mechanisms , 2001 .

[7]  Sridhar Kota,et al.  Design of Compliant Mechanisms: Applications to MEMS , 2001 .

[8]  Brian D. Jensen,et al.  Microelectromechanical high-density energy storage/rapid release system , 1999, Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components.

[9]  Larry L. Howell,et al.  A Method for the Design of Compliant Mechanisms With Small-Length Flexural Pivots , 1994 .

[10]  M. Madou.  Fundamentals of microfabrication , 1997 .

[11]  N. Kikuchi,et al.  Structural Optimization Considering Flexibility. (Integrated Design Method for Compliant Mechanisms). , 1998 .

[12]  O. Sigmund,et al.  Design and fabrication of compliant micromechanisms and structures with negative Poisson's ratio , 1996, Proceedings of Ninth International Workshop on Micro Electromechanical Systems.

[13]  Sridhar Kota,et al.  An Energy Formulation for Parametric Size and Shape Optimization of Compliant Mechanisms , 1999 .

[14]  S. Senturia.  Microsystem Design , 2000 .

[15]  Niels Olhoff,et al.  Topology optimization of continuum structures: A review* , 2001 .

[16]  R. Peterson,et al.  Stress Concentration Factors , 1974 .