A reprogrammable microactuator system is presented,consisting of antagonistic shape memory alloy(SMA)microactuators for bidirectional folding of miniature-scale tiles following the concept of origami.Additional integr...A reprogrammable microactuator system is presented,consisting of antagonistic shape memory alloy(SMA)microactuators for bidirectional folding of miniature-scale tiles following the concept of origami.Additional integrated heatable soft-magnetic pads with low ferromagnetic transition temperature allow for control of magnetic latching forces.The strongly coupled thermo-mechanical and thermo-magnetic properties of the microactuator and magnetic subsystems are taken into account in a model-based design to enable their selective control by Joule heating.A procedure for local shape setting of the SMA microactuators is presented to adjust their memory shape at either maximum or minimum bending angle and,thus,to functionalize their performance as protagonists or antagonists.A microfabrication process is developed that takes the specific requirements for processing the various materials and structures into account.A demonstrator system consisting of four triangular tiles with an edge length of 500μm and an angular range of about±100°is introduced that is programmed to adopt the shape of a pyramid and later on reprogrammed to self-unlatch,self-unfold,and subsequently to adopt the shape of a table.展开更多
Conformational flexibility is essential to the stimuli-responsive property of organic materials,but achieving the reversible molecular transformation is still challenging in functional materials for the high energy ba...Conformational flexibility is essential to the stimuli-responsive property of organic materials,but achieving the reversible molecular transformation is still challenging in functional materials for the high energy barriers and restriction by intermolecular interactions.Herein,through the incorporation of various steric hindrances into phenothiazine derivatives with different positions and quantities to tune the molecular conformations by adjustable repulsive forces,the folded angles gradually changed from 180°to 90°in 17 compounds.When the angle located at 112°with moderated steric effect,dynamic and reversible transformation of conformations under mechanical force has been achieved for the low energy barriers and mutually regulated molecular motions,resulting in both selfrecoverable and stimuli-responsive phosphorescence properties for the first time.It opened up a new way to realize the self-recovery property of organic materials,which can facilitate the multi-functional property of smart materials with the opened avenue for other fields with inspiration.展开更多
基金funded by the German Science Foundation within the Priority Program“Cooperative Multistage Multistable Microactuator Systems”(SPP2206)partly carried out with the support of the Karlsruhe Nano Micro Facility(KNMFi,www.knmf.kit.edu),a Helmholtz Research Infrastructure at Karlsruhe Institute of Technology(KIT,www.kit.edu)funding by the German Science Foundation(DFG)through the project 413288478.
文摘A reprogrammable microactuator system is presented,consisting of antagonistic shape memory alloy(SMA)microactuators for bidirectional folding of miniature-scale tiles following the concept of origami.Additional integrated heatable soft-magnetic pads with low ferromagnetic transition temperature allow for control of magnetic latching forces.The strongly coupled thermo-mechanical and thermo-magnetic properties of the microactuator and magnetic subsystems are taken into account in a model-based design to enable their selective control by Joule heating.A procedure for local shape setting of the SMA microactuators is presented to adjust their memory shape at either maximum or minimum bending angle and,thus,to functionalize their performance as protagonists or antagonists.A microfabrication process is developed that takes the specific requirements for processing the various materials and structures into account.A demonstrator system consisting of four triangular tiles with an edge length of 500μm and an angular range of about±100°is introduced that is programmed to adopt the shape of a pyramid and later on reprogrammed to self-unlatch,self-unfold,and subsequently to adopt the shape of a table.
基金supported by the National Natural Science Foundation of China(22122504,22235006)Foundation of Hubei Scientific Committee(2022BAA015 and 2022EHB010).
文摘Conformational flexibility is essential to the stimuli-responsive property of organic materials,but achieving the reversible molecular transformation is still challenging in functional materials for the high energy barriers and restriction by intermolecular interactions.Herein,through the incorporation of various steric hindrances into phenothiazine derivatives with different positions and quantities to tune the molecular conformations by adjustable repulsive forces,the folded angles gradually changed from 180°to 90°in 17 compounds.When the angle located at 112°with moderated steric effect,dynamic and reversible transformation of conformations under mechanical force has been achieved for the low energy barriers and mutually regulated molecular motions,resulting in both selfrecoverable and stimuli-responsive phosphorescence properties for the first time.It opened up a new way to realize the self-recovery property of organic materials,which can facilitate the multi-functional property of smart materials with the opened avenue for other fields with inspiration.
