title: Influences of Substrate Adhesion and Particle Size on the Shape Memory Effect of Polystyrene Particles.
abstract: Formulations and applications of micro- and nanoscale polymer particles have proliferated rapidly in recent years, yet knowledge of their mechanical behavior has not grown accordingly. In this study, we examine the ways that compressive strain, substrate surface energy, and particle size influence the shape memory cycle of polystyrene particles. Using nanoimprint lithography, differently sized particles are programmed into highly deformed, temporary shapes in contact with substrates of differing surface energies. Atomic force microscopy is used to obtain in situ measurements of particle shape recovery kinetics, and scanning electron microscopy is employed to assess differences in the profiles of particles at the conclusion of the shape memory cycle. Finally, finite element models are used to investigate the growing impact of surface energies at smaller length scales. Results reveal that the influence of substrate adhesion on particle recovery is size-dependent and can become dominating at submicron length scales.
authors.affiliation: Department of Mechanical Engineering and ‡Material Science and Engineering Program, University of Colorado at Boulder , Boulder, Colorado 80309-0427, United States.|Applied Chemicals and Materials Division and §Radio Frequency Technology Division, National Institute of Standards and Technology , Boulder, Colorado 80305, United States.
authors.forename: Lewis M
authors.initials: LM
authors.lastname: Cox
authors.affiliation: Department of Mechanical Engineering and ‡Material Science and Engineering Program, University of Colorado at Boulder , Boulder, Colorado 80309-0427, United States.|Applied Chemicals and Materials Division and §Radio Frequency Technology Division, National Institute of Standards and Technology , Boulder, Colorado 80305, United States.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Killgore
authors.affiliation: Department of Mechanical Engineering and ‡Material Science and Engineering Program, University of Colorado at Boulder , Boulder, Colorado 80309-0427, United States.|Applied Chemicals and Materials Division and §Radio Frequency Technology Division, National Institute of Standards and Technology , Boulder, Colorado 80305, United States.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Mechanical Engineering and ‡Material Science and Engineering Program, University of Colorado at Boulder , Boulder, Colorado 80309-0427, United States.|Applied Chemicals and Materials Division and §Radio Frequency Technology Division, National Institute of Standards and Technology , Boulder, Colorado 80305, United States.
authors.forename: Rong
authors.initials: R
authors.lastname: Long
authors.affiliation: Department of Mechanical Engineering and ‡Material Science and Engineering Program, University of Colorado at Boulder , Boulder, Colorado 80309-0427, United States.|Applied Chemicals and Materials Division and §Radio Frequency Technology Division, National Institute of Standards and Technology , Boulder, Colorado 80305, United States.
authors.forename: Aric W
authors.initials: AW
authors.lastname: Sanders
authors.affiliation: Department of Mechanical Engineering and ‡Material Science and Engineering Program, University of Colorado at Boulder , Boulder, Colorado 80309-0427, United States.|Applied Chemicals and Materials Division and §Radio Frequency Technology Division, National Institute of Standards and Technology , Boulder, Colorado 80305, United States.
authors.forename: Jianliang
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Mechanical Engineering and ‡Material Science and Engineering Program, University of Colorado at Boulder , Boulder, Colorado 80309-0427, United States.|Applied Chemicals and Materials Division and §Radio Frequency Technology Division, National Institute of Standards and Technology , Boulder, Colorado 80305, United States.
authors.forename: Yifu
authors.initials: Y
authors.lastname: Ding