Designing Developable Mechanisms From Flat Patterns

Abstract

This paper presents tools and methods to design cylindrical and conical developable mechanisms from flat, planar patterns. Equations are presented that relate the link lengths and link angles of planar and spherical mechanisms to the dimensions in a flat configuration. These flat patterns can then be formed into curved, developable mechanisms. Guidelines are established to determine if a mechanism described by a flat pattern can exhibit intramobile or extramobile behavior. A developable mechanism can only potentially exhibit intramobile or extramobile behavior if none of the links extend beyond half of the flat pattern. The behavior of a mechanism can change depending on the location of the cut of the flat pattern. Different joint designs are discussed including lamina emergent torsional (LET) joints. Physical examples are presented.

Soft Coiled Pneumatic Actuator with Integrated Length-Sensing Function for Feedback Control

“…This method was analyzed for use in origami applications [34] and has been demonstrated in a medical support system to mitigate buckling [35], lamina emergent origami [36], and in developable mechanisms [37]. This simple plastic annealing process can be very useful as it can change the energy behavior of the material, allowing the user to select different stable and unstable states [38].…”