New material shape-shifts at predetermined time
DOI: 10.1063/PT.5.0210130
BBC : Shape-shifting materials typically require an external trigger to initiate the shape change. Now Sergei Sheiko of the University of North Carolina at Chapel Hill and his colleagues have developed a polymer in which the transformation occurs at a predetermined time with no outside stimuli necessary. The researchers created a polymer with two types of chemical bonds: permanent and dynamic. The permanent bonds define the material’s final shape; the dynamic bonds control how quickly the material can reach that shape, depending on the strength and concentration of the bonds. The timing precision is limited to a scale of minutes to hours, but that may be sufficient for the material to be used for applications such as drug delivery.
