Limited resources are currently available to assist engineers in implementing compliant members into mechanical designs. As a result, engineers often have little to no direction incorporating compliant mechanisms. This thesis develops a conceptual design framework and process that utilizes a proposed classification scheme and a library of mechanisms to help engineers incorporate compliant mechanisms into their applications. As the knowledge related to the synthesis and analysis of compliant mechanisms continues to grow and mature, and through the classification scheme established in this thesis, compliant mechanisms may become more extensively used in commercial mechanical designs. This thesis also demonstrates a design approach engineers can use to convert an existing rigid-body mechanism into a compliant mechanism by using the established classification scheme and a library of compliant mechanisms. This approach proposes two possible techniques that use rigid-body replacement synthesis in conjunction with a compliant mechanism classification scheme. One technique replaces rigid-body elements with a respective compliant element. The other technique replaces a complex rigid-body mechanism by decomposing the mechanism into simpler functions and then replacing a respective rigid-body mechanism with a compliant mechanism that has a similar functionality. These techniques are then demonstrated by developing and designing a competitive and feasible compliant road bicycle brake system.

Lamina emergent mechanisms (LEMs) are a maturing technology that is prepared for commercial implementation into new products. LEMs are defined by three functional characteristics; they (1) are compliant, (2) are fabricated from planar materials, and (3) emerge from a flat initial state. Advantages, design challenges, and design tools are described for each of the functional characteristics. Opportunities for LEMs are discussed, namely disposable LEMs, novel arrays of LEMs, scaled LEMs, LEMs with surprising motion, shock absorbing LEMs, and deployable LEMs. Technology push product development processes were employed to select applications for LEMs. LEM technology was characterized. In a LEM workshop, eighteen industry professionals then helped identify over 200 potential applications for the technology. The applications were evaluated, and the most promising ideas that were identified for each LEM opportunity are described with graphics of possible product embodiments. Of the various product opportunities enabled by LEMs, deployable mechanisms – particularly in the credit card size – are among the most viable. The compactness and portability of credit-card-sized products create a strong motivation for their development. Expanding the capabilities of credit-card-sized mechanisms to include more sophisticated motions and a broader range of tasks may dramatically increase their market potential. A review of the current state-of-the-art in credit-card-sized mechanisms reveals two primary classes of mechanisms most commonly used in this form factor: rigid-body mechanisms and in-plane compliant mechanisms. The limitations of each and corresponding LEM advantages are described. Criteria for determining whether a product is a suitable candidate for using LEM technology to create or improve a credit-card-sized product are established. The advantages of LEMs in credit-card-sized products are illustrated through an example product: a compact lancing device that could be used as a main component for a highly portable epinephrine syringe.

This work explores the use of carbon-infiltrated carbon nanotube (CI-CNT) forests as a material for fabricating compliant MEMS devices. The impacts of iron catalyst layer thickness and carbon infiltration time are examined. An iron layer of 7nm or 10nm with an infiltration time of 30 minutes produces CI-CNT best suited for compliant applications. Average maximum strains of 2% and 2.48% were observed for these parameters. The corresponding elastic moduli were 5.4 GPa and 4.1 GPa, respectively. A direct comparison of similar geometry suggested CI-CNT is 80% more flexible than single-crystal silicon. A torsional testing procedure provided an initial shear modulus of about 5 GPa for the 7-nm, 30-min CI-CNT. The strain and elastic modulus values were used to design numerous functional devices which were then fabricated in CI-CNT. A series of compliant cell restraint mechanisms were developed, assessed, and revised. A passive restraint with no moving parts was found to be both the most effective design and the easiest design to produce economically. A refined version of the passive restraint has been released commercially. Another series of designed devices successfully demonstrates the implementation of CI-CNT LEM designs.