Collective dynamics of confined colloids is crucial in diverse scenarios such as self-assembly and phase behavior in materials science, microrobot swarms for drug delivery, and microfluidic control. Yet, fine-tuning the dynamics of colloids in microscale confined spaces is still a formidable task due to the complexity of the dynamics of colloidal suspension and to the lack of methodology to probe colloids in confinement. Here, we show that the collective dynamics of confined magnetic colloids can be finely tuned by external magnetic fields. In particular, the mechanical properties of the confined colloidal suspension can be probed in real-time and this strategy can be also used to tune microscale fluid transport. Our experimental and theoretical investigations reveal that the collective configuration characterized by the colloidal entropy is controlled by the colloidal concentration, confining ratio, and external field strength and direction. Indeed, our results show that mechanical properties of the colloidal suspension as well as the transport of the solvent in microfluidic devices can be controlled upon tuning the entropy of the colloidal suspension. Our approach opens new avenues for the design and applications of drug delivery, microfluidic logic, dynamic fluid control, chemical reaction, and beyond.

Rapid progress toward smart membranes has been made in the past few decades, of which the liquid gating membranes have attracted increasing attention because of their smart permeability. However, the current liquid gating membranes are mainly focused on the control of transmembrane performance, whereas the motion behaviors of such membranes that respond to ambient gas pressure are also very important for many applications in industry. Here, we developed a mobile liquid gating membrane system driven by dynamic changes in ambient gas pressure that can move as a piston depending on gas pressure. We further investigated the influences of membrane pore sizes and gating liquid types on the motion behavior of mobile liquid gating membranes. By incorporating with pneumatic elastomers, the liquid gating membrane system shows bistable gas transport properties that can serve as a smart valve. We believe the mobile liquid gating membrane system can provide a new platform for integrating simple control and logic function of soft actuators and robots.

pores distributed randomly or uniformly, both gases and liquids can be transported and released in a controlled manner through liquid gate drawing on the partnership of static solid porous membranes with dynamic adaptive liquids. [2] The dynamic interfacial interaction between these two phases contributes to the development and design of sophisticated and versatile liquid gating membrane systems, enabling them to create new opportunities for smart materials and find ways into increasing energy, biomedical, and environmental and resource management scenarios, such as multiphase separation, [3] drug delivery, [4] chemical detection, [5] and chemical reaction. [6] In pursuit of further advancing diversified functions and bringing widespread applications, the common strategy is to develop smart liquid gating membranes in response to a single or multiple synergistic external stimuli, [1a,7] such as light, temperature, electric fields, magnetic fields, pH, and specific ions/molecules. [8] General approaches for the responsive interface design of smart liquid gating membranes have focused on responsive gating liquid design and responsive solid porous membrane design. [2c,9] Recent works have achieved some steps toward this approach. For example, relying on the 1D or 2D stretching deformation of an elastomeric material in response to a mechanical stimulus, a liquid gating elastomeric porous membrane system has Liquid gating membranes have been demonstrated to show unprecedented properties of dynamicity, stability, adaptivity, and stimulus-responsiveness. Most recently, smart liquid gating membranes have attracted increasing attention to bring some brand-new properties for real-world applications, and various environment-driven systems have been created. Here, a self-driven system of a smart liquid gating membrane is further developed by designing a new sytem based on a liquid gating magnetoelastic porous membrane with reversible meniscus-shaped deformations, and it is not subject to the complex gating liquid restriction of magnetorheological fluids. Compared with other systems, this magnetic-responsive self-driven system has the advantage that it provides a universal and convenient way to realize active regulation of gas/liquid release. Experiments and theoretical calculations demonstrate the stability, the nonfouling behavior, and the tunability of the system. In addition, this system can be used to perfectly open and close gas transport, and the gating pressure threshold for the liquid release can be reduced under the same conditions. Based on the above capabilities, combined with the fast and 3D contactless operation, it will be of benefit in fields ranging from visible gas/liquid mixture content monitoring and energy-saving multiphase separation, remote fluid release, and beyond.

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The newly designed structures are employed to improve the high pressure turbine (HPT) disk to the expected performance. The twin-web disk (TWD) has been proven to be the future trend of the HPT disk due to its breakthrough in weight loss, strength and heat transfer efficiency compared to the conventional single web disk (SWD). Because of the multi-physics working conditions and intense coupling of multiple disciplines, the conventional design of the HPT disk is a labor intensive work. A series of design procedures, including asymmetrical computational fluid dynamics (CFD) analysis, inverse distance weighted (IDW) interpolation method, multidisciplinary feasible method (MDF), and design of experiments (DOE), are proposed to obtain the proper design for both TWD and SWD in an efficient way. In the present work, the multidisciplinary design of optimization (MDO) has been performed to find the proper shape of the TWD disk with the minimum mass. The results showed that the TWD exhibits a better performance in heat transfer and weight loss than SWD. The modeling and optimization procedure of this work can be referred for engineering design.