Bistable Configurations of Compliant Mechanisms Modeled Using Four Links and Translational Joints

Bistable mechanical devices remain stable in two distinct positions without power input.They find application in valves, switches, closures, and clasps. Mechanically bistablebehavior results from the storage and release of energy, typically in springs, with stablepositions occurring at local minima of stored energy. Compliant mechanisms offer anelegant way to achieve this behavior by incorporating both motion and energy storageinto the same flexible element. Interest in compliant bistable mechanisms has also recentlyincreased because of the advantages of bistable behavior in many micro-electro-mechanical systems (MEMS). Design of compliant or rigid-body bistable mechanismstypically requires simultaneous consideration of both energy storage and motion require-ments. This paper simplifies this process by developing theory that provides prior knowl-edge of mechanism configurations that guarantee bistable behavior. Configurations whichinclude one or more translational, or slider, joints are studied in this work. Severaldifferent mechanism types are analyzed to determine compliant segment placement thatwill ensure bistable mechanism operation. Examples demonstrate the power of the theoryin design. @DOI: 10.1115/1.1760776#

[1]  L. Howell,et al.  On-chip actuation of an in-plane compliant bistable micromechanism , 2002 .

[2]  Carey W. King,et al.  Analysis of multiple equilibrium positions in magnetostatic field , 2003, DAC 2003.

[3]  Massimo Piotto,et al.  A micromachined bistable 1×2 switch for optical fibers , 2000 .

[4]  T. E. Shoup,et al.  A survey of flexible link mechanisms having lower pairs , 1971 .

[5]  Larry L. Howell,et al.  Identification of compliant pseudo-rigid-body four-link mechanism configurations resulting in bistable behavior , 2003 .

[6]  B. Halg,et al.  On a nonvolatile memory cell based on micro-electro-mechanics , 1990, IEEE Proceedings on Micro Electro Mechanical Systems, An Investigation of Micro Structures, Sensors, Actuators, Machines and Robots..

[7]  Y. Bäcklund,et al.  A lateral symmetrically bistable buckled beam , 1998 .

[8]  Larry L. Howell,et al.  Design of two-link, in-plane, bistable compliant micro-mechanisms , 1999 .

[9]  Larry L. Howell,et al.  Evaluation of equivalent spring stiffness for use in a pseudo-rigid-body model of large-deflection compliant mechanisms , 1996 .

[10]  K. R. Farmer,et al.  A bistable microrelay based on two-segment multimorph cantilever actuators , 1998, Proceedings MEMS 98. IEEE. Eleventh Annual International Workshop on Micro Electro Mechanical Systems. An Investigation of Micro Structures, Sensors, Actuators, Machines and Systems (Cat. No.98CH36176.

[11]  W. Menz,et al.  Microvalves with bistable buckled polymer diaphragms , 1996 .

[12]  Larry L. Howell,et al.  Reliability-based optimal design of a bistable compliant mechanism , 1993 .

[13]  Larry L. Howell,et al.  AN INVESTIGATION INTO COMPLIANT BISTABLE MECHANISMS , 1998 .

[14]  Steven Dubowsky,et al.  Optimized binary modular reconfigurable robotic devices , 2003 .

[15]  Hiroyuki Fujita,et al.  Self-aligned vertical mirror and V-grooves applied to an optical-switch: modeling and optimization of bi-stable operation by electromagnetic actuation , 2001 .

[16]  Larry L. Howell,et al.  Prediction of the First Modal Frequency of Compliant Mechanisms Using the Pseudo-Rigid-Body Model , 1999 .

[17]  A. Midha,et al.  Parametric Deflection Approximations for End-Loaded, Large-Deflection Beams in Compliant Mechanisms , 1995 .

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

[20]  J. Qiu,et al.  A centrally-clamped parallel-beam bistable MEMS mechanism , 2001, Technical Digest. MEMS 2001. 14th IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.01CH37090).

[21]  T. Abe,et al.  A proportional microvalve using a bi-stable magnetic actuator , 1997, Proceedings IEEE The Tenth Annual International Workshop on Micro Electro Mechanical Systems. An Investigation of Micro Structures, Sensors, Actuators, Machines and Robots.

[22]  Larry L. Howell,et al.  A Pseudo-Rigid-Body Model for Initially-Curved Pinned-Pinned Segments Used in Compliant Mechanisms , 2001 .

[23]  Werner Karl Schomburg,et al.  Design optimization of bistable microdiaphragm valves , 1998 .

[24]  Hans Joachim Quenzer,et al.  Bistable microvalve with pneumatically coupled membranes , 1996, Proceedings of Ninth International Workshop on Micro Electromechanical Systems.

[25]  Chang-Jin Kim,et al.  A bistable snapping microactuator , 1994, Proceedings IEEE Micro Electro Mechanical Systems An Investigation of Micro Structures, Sensors, Actuators, Machines and Robotic Systems.

[26]  M. Saif.  On a tunable bistable MEMS-theory and experiment , 2000, Journal of Microelectromechanical Systems.

[27]  Larry L. Howell,et al.  A Loop-Closure Theory for the Analysis and Synthesis of Compliant Mechanisms , 1996 .

[28]  Oliver Paul,et al.  Mechanical properties of thin films from the load deflection of long clamped plates , 1998 .

[29]  W. Fang,et al.  Comments on measuring thin-film stresses using bi-layer micromachined beams , 1995 .

[30]  L. Howell,et al.  A self-retracting fully compliant bistable micromechanism , 2003 .

[31]  M. Hoffmann,et al.  Optical fibre switches based on full wafer silicon micromachining , 1999 .