Shape Transformations of Nemato-elastic Sheets and Textiles

Date7th Jan. 2019
VenueRoom 118, Building 12, Yuquan Campus
SpeakerProf. Leonid M. Pismen (Technion-Israel Institute of Technology)
AbstractLiquid crystal elastomers, made of cross-linked polymeric chains with embedded mesogenic structures, combine orientational properties of liquid crystals with shear strength of solids. Their  flexibility and sensitivity to chemical and physical signals comes close to that of biological tissues. Reshaping of nemato-elastic sheets or shells opens ways of creating a variety of forms that can be manipulated by imprinting a pattern, boundary anchoring, positioning of defects, and doping. Reversible local phase transitions causing repeated reshaping can be used to construct soft crawling and swimming robots with the gait and speed dependent on flexural rigidity and substrate friction. Still more flexible shape transformations unimpeded by area or volume conservation are possible in textiles actuated by of Janus fibers that combine stimuli-responsive and passive materials. Under certain conditions, alternative equilibrium states, one absolutely stable and the others metastable coexist, and their relative energy may flip its sign as the system parameters, such as the extension upon actuation, change.

Professor of Department of Chemical Engineering, Technion–Israel Institute of Technology, Haifa. Senior Research Associate, Institute of Electrochemistry of the USSR Academy of Sci-ences, Moscow, Theoretical Department; Distinguished Visiting Scholar, Department of Applied Mathematics and Engineering Science, Northwestern University, Evanston IL Mar–Jun 1999.

Research projects

Self-organized patterns and three-dimensional structures in nematic elastomers, funded by Israel Science Foundation (2014 -2018)

Principles of structure formation in complex systems, funded by Perm Region, Russia (2012 -2017)

Multiscale mechanisms of epithelial patterning and morphogenesis: theory and experi-ments, funded by Human Frontier Science Program (2009–2012)

Mesoscopic hydrodynamics of thin .lms, funded by Israeli Science Foundation (2002– 2006)

Self-organization phenomena in catalytic surface reactions: from nanoscale to microscale, funded by GIF (2000–2003).

Patterns and Defects in Nonlinear Systems, funded by Minerva Foundation (1995–2011)