Ximin He

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In this paper, we demonstrate a double nanoimprinting process that allows the formation of nanostructured polymer heterojunctions of composition and morphology that can be selected independently. We fabricated photovoltaic (PV) devices with extremely high densities (10(14)/mm(2)) of interpenetrating nanoscale columnar features in the active polymer blend(More)
In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: Keywords: Adaptive and dynamic architectures Environmentally responsive systems(More)
The control of the cell microenvironment on model patterned substrates allows the systematic study of cell biology in well defined conditions, potentially using automated systems. The extreme protein resistance of poly(oligo(ethylene glycol methacrylate)) (POEGMA) brushes is exploited to achieve high fidelity patterning of single cells. These coatings can(More)
Living organisms have unique homeostatic abilities, maintaining tight control of their local environment through interconversions of chemical and mechanical energy and self-regulating feedback loops organized hierarchically across many length scales. In contrast, most synthetic materials are incapable of continuous self-monitoring and self-regulating(More)
A necessity of all living organisms from prokaryotes to mammals is the capability to respond rapidly to a changing environment via a variety of adaptive mechanisms. At the core of this adaptive nature are hierarchical signaling cascades that allow the organism to transform a stimulus signal into a variety of outputsoften visible or otherwise detectable(More)
The ability to manipulate the movement of surface microstructures is essential for the development of dynamic, responsive materials. We demonstrate that in addition to bulk actuation upon drying, a unique type of highly localized, directional actuation can be achieved when microstructures embedded in pH responsive gel are exposed to pH gradients. Theory and(More)
The efficient extraction of (bio)molecules from fluid mixtures is vital for applications ranging from target characterization in (bio)chemistry to environmental analysis and biomedical diagnostics. Inspired by biological processes that seamlessly synchronize the capture, transport and release of biomolecules, we designed a robust chemomechanical sorting(More)
A polypyrrole (PPy) composite film with a pure PPy zone and a PPy–TiO 2 nanoparticle composite zone in its cross-sectional direction was synthesized by direct oxidation of pyrrole successively in an electrolyte with or without TiO 2 nanoparticles. The volume content of TiO 2 in the composite film was tested to be lower than 0.9%. The actuator fabricated(More)
A new methodology to create 3D origami patterns out of Si nanomembranes using pre-stretched and pre-patterned polydimethylsiloxane substrates is reported. It is shown this approach is able to mimic paper-based origami patterns. The combination of origami-based microscale 3D architectures and stretchable devices will lead to a breakthrough on reconfigurable(More)