Abstract of the thesis:
In this thesis, it is explaining that the fabrication and testing of a tunably-compliant tendon-driven nger implemented through the geometric design of a skeleton made of the low melting point Field’s metal encased in a silicone rubber. The initial prototype consists of a skeleton comprised of two rods of the metal, with heating elements in thermal contact with the metal at various points along its length, embedded in an elastomer. The inputs to the systems are both the force exerted on the tendon to bend the nger and the heat introduced to liquefy the metal locally or globally along the length of the nger. Selective localized heating allows multiple joints to be created along the length of the finger.
Fabrication was accomplished via a multiple step process of elastomer casting and liquid metal casting. Heating elements such as power resistors or Ni-Cr wire with electrical connections were added as an intermediate step before the nal elastomer casting. The addition of a tradition tendon actuation was inserted after all casting steps had been completed. While preliminary, this combination of selective heating and engineered geometry of the low-melting point skeletal structure will allow for further investigation into the skeletal geometry and its effects on local and global changes in device stiness.
Abstract of this thesis:
The ability to change stiffness is a capability exhibited through the animal kingdom, with many recent advances in tunable stiffness in the area of robotics. This report describes and demonstrates a mechanism design that provides the ability to make modular subcomponents with tunable stiffness by creating a bi-stable mechanism that exhibits different stiffnesses in each of the stable configurations. The design is based on controlled buckling of two linear springs in series and allows design-time control over the stiffnesses, equilibrium points, and energy required to transition between the stable configurations. A prototype mechanism was designed and experimental data was obtained. This project demonstrates the bi-stably and tunability of the buckling spring mechanism.