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Incorporating thermoplastic materials with shape memory properties into the fused filament fabrication process enables what is commonly referred to as 4D printing. When the blends are composed of one or more materials with inherent shape memory properties, the tailoring of critical parameters such as shape recovery temperature can be realized. Previous work by our group demonstrated the creation of shape memory polymer blends where one component was elastomeric. The following work entails the development and characterization of rigid polyester blends that are biocompatible and biodegradable in addition to having shape memory properties. Dynamic mechanical analysis (DMA) was used to determine the critical deformation and recovery temperatures. The effect of print raster patterns on the DMA results was also evaluated. Micro- tensile testing was used to characterize the physical properties of the materials at elevated temperatures. Finally, scanning electron microanalysis was used to examine the fracture surfaces of spent tensile specimens. 

Abstract Undergraduate mechanical engineering students struggle in comprehending the fundamentals presented in an introductory level mechanical vibrations course which eventually affects their performance in the posterior courses such as control theory. One salient factor to this is missing the visualization of the concept with hands-on learning since the vibrations and control laboratory course is offered in the following semester. This study presents the design, development of three portable and 3D-printed compliant vibratory mechanisms actuated by a linear motor and their implementation in vibrations course and vibrations and control laboratory. The proposed setups consist of flexible and compliant springs, sliders, and base support. Mechanisms are utilized to demonstrate free and forced vibrations, resonation, and design of a passive isolator. In addition to the 3D-printed, portable lab equipment, we created the Matlab Simscape GUI program of each setup so instructors can demonstrate the fundamentals in the classroom, assign homework, project, in-class activity or design laboratory.