Gradient Porous Elastic Hydrogels with Shape‐Memory Property and Anisotropic Responses for Programmable LocomotionRongcong Luo, Jin Wu, Ngoc‐Duy Dinh et al.|Advanced Functional Materials|2015 Programmable locomotion of responsive hydrogels has gained increasing attention for potential applications in soft robotics, microfluidic components, actuators, and artificial muscle. Modulation of hydrogel pore structures is essential for tailoring their mechanical strength, response speeds, and motion behaviors. Conventional methods forming hydrogels with homogeneous or stepwise‐distributed pore structures are limited by the required compromise to simultaneously optimize these aspects. Here, a heterobifunctional crosslinker enabled hydrothermal process is introduced to synthesize responsive hydrogels with well‐defined gradient pore construction. According to gradient porosity controls, the hydrogels simultaneously exhibit rapid responses to external stimuli, high elasticity/compressibility, and programmable locomotion capability. By incorporating polypyrrole nanoparticles as photothermal transducers, photo/thermal responsive composite hydrogels are formed to enable programmable control of locomotion such as bending, curving, twisting, and octopus‐like swimming under near‐infrared laser stimulation. The tunable pore structures, mechanical properties, and locomotion of this new class of materials make these gradient porous hydrogels potentially suitable for a variety of applications.
A flexible multiplexed immunosensor for point-of-care in situ wound monitoringYuji Gao, Dat T. Nguyen, Trifanny Yeo et al.|Science Advances|2021 ), and physicochemical parameters (temperature and pH) with a microfluidic wound exudate collector and flexible electronics for wireless, smartphone-based data readout. We demonstrate in situ multiplexed monitoring in a mouse wound model and also profile wound exudates from patients with venous leg ulcers. This technology may facilitate more timely and personalized wound management to improve chronic wound healing outcomes.
Microfluidic Assembly of Magnetic Hydrogel Particles with Uniformly Anisotropic StructureMonodisperse magnetic particles are templated from double emulsions formed using sequential flow-focus drop formation. The microfluidic drop formation allows the particles to be formed with high monodispersity and with consistently anisotropic internal structure. This structural anisotropy gives rise to magnetic anisotropy, allowing the particles to be rotated by a magnetic field.
Droplet Microfluidics for Fabrication of Non‐Spherical ParticlesHo Cheung Shum, Adam R. Abate, Daeyeon Lee et al.|Macromolecular Rapid Communications|2009 We describe new developments for controlled fabrication of monodisperse non-spherical particles using droplet microfluidics. The high degree of control afforded by microfluidic technologies enables generation of single and multiple emulsion droplets. We show that these droplets can be transformed to non-spherical particles through further simple, spontaneous processing steps, including arrested coalescence, asymmetric polymer solidification, polymerization in microfluidic flow, and evaporation-driven clustering. These versatile and scalable microfluidic approaches can be used for producing large quantities of non-spherical particles that are monodisperse in both size and shape; these have great potential for commercial applications.
Janus Particles Templated from Double Emulsion Droplets Generated Using MicrofluidicsWe present a simple microfluidics-based technique to fabricate Janus particles using double-emulsion droplets as templates. Since each half of the particles is templated from a different immiscible fluid, this method enables the formation of particles from two materials with vastly different properties. The use of microfluidics affords excellent control over the size, morphology, and monodispersity of the particles.