Abstract:
The project proposes to model, design and experimentally test several planar compliant mechanisms that are aimed at amplifying the input mechanical motion.  Such compliant mechanisms use flexure hinges (which are slender, flexible portions that can bend and enable relative rotation between two adjacent rigid links) instead of classical rotation joints.  They are modern devices being applied in precision positioning as well as in micro/nano electromechanical systems (MEMS/NEMS).  The focus of this project will be on compliant mechanisms that have two stages of motion amplification wand which have double symmetry, realizing thus an amplified output motion which is parallel to the input one.  Various flexure hinges (such as right-circular, corner-filleted and elliptic) will be implemented in these compliant mechanisms.  Two models will be developed to assist with the subsequent design process.  One simplified model will consider the flexure as being point-like, whereas the second model will be precise and will be based on the real dimensions and shape of the flexure hinges.  Each model will predict the mechanical amplification (or advantage).  Several compliant mechanisms will be selected from the model/analysis pool and execution drawings will be produced and sent via email to the company which will fabricate these mechanisms by electric discharge machining (EDM).  The fabricated mechanisms will then be tested in the School of Engineering’s labs at UAA.  A first round of testing will apply simple mechanical actuation and measuring of the input/output motion, whereas in a second testing set actuation by linear actuators (voice coils) will be used.  The experimental results are going to be compared with the model data and conclusions will be derived with respect to the obtained results.  The specific aims of this project are:

(a)    Formulation of a simple model predicting the motion amplification by the two-stage flexure-based planar compliant mechanisms in the case the flexure hinges are considered point-like

(b)    Formulation of an exact model for the motion amplification of these mechanisms by using real flexure hinges of various configurations (right-circular, corner-filleted, elliptic)

(c)    Identification of a set of compliant mechanisms to be designed and tested, and production of execution drawings

(d)    Experimental testing of the fabricated devices by using simple mechanical actuation and then electro-mechanical linear actuation through voice-coils

(e)    Evaluation of model and experimental results and identification of causes for possible differences between the two methods

Jennifer Lane Jemison – BS Civil Engineering: "Tidal Basin Power Generator Project"
Faculty Mentor: Nyree McDonald
Final Report

Abstract:
The world’s most predictable energy resource comes in the form of the ebbing and flooding of the tides.  Every 12.5 hours the cycle repeats.  It is this predictability that makes the concept of harnessing energy from the tides attractive.  In recent years, the study of the energy of waves and tides has come to the forefront of energy engineering.  Many methods have been designed and developed to change the mechanical energy of the moving water into electrical power.  Some systems use the action of the waves, while others focus on the potential energy from the difference in the height of the tides. The Knik Arm has a 48ft difference in tidal heights, one of the larges in the world.  This makes it a perfect place to pilot a system that exploits the potential energy locked within the tides.  Before this can become a reality, a thorough study must be completed to determine the capacity and efficiency of a tidal basin power generation system for the Knik Arm near Anchorage, Alaska.  First, a design must be completed to theoretically maximize electrical output.  Second, a lab scale model should be built to experiment with the theoretical design.  And last, the testing should be done to determine the potential output and efficiency of a tidal basin power generator.