Leng Jinsong

Adaptive optical properties of ER fluid incorporating composite particles

Abstract Electrorheological (ER) fluid is one of the popular materials used in smart materials and structures. The material properties of ER fluid can be changed markedly while an external electric field is imposed on ER fluid domain. In this paper, the optical properties of ER suspensions consisting of composite particles dispersed in silicone oil are investigated. Both dc and ac electric fields are utilized to be imposed on ER fluid. The transmissivity of light through ER fluid under various electric fields is detected and analyzed. It is shown that the transmissivity of light increases with the increasing electric field strength and time. The change of transmissivity is caused by the formation of particle chains. The higher the particle concentration, the faster the change occurs. When an ac electric field is applied, the transmissivity can be affected by the frequency of electric field.

Development of shape memory polymers micro/nanofiber membranes in biomedical applications

As a class of smart materials, shape memory polymers (SMPs) can remember the temporary shape and return to the original shape under the condition of the external stimuli. The shape memory micro/nanofibers prepared by electrospinning technology possess a three-dimensional structure which is similar to the natural extracellular matrix. Therefore, it shows great application prospect in the biomedical field, especially in tissue engineering. Moreover, shape memory micro/nanofiber membranes bring more and more opportunities for the rapid development of personalized and smart biomedical devices. This paper reviews of SMP micro/nanofiber membranes, including preparation, structure, morphology and driving methods. We also summarize the applications of SMP micro/nanofiber membranes in the brackets of bone tissue, bone tissue repair, nerve scaffolds and cell culture research. Furthermore, analysis other structures used in the biomedical field are discussed. Finally, we conclude the challenges and the perspectives of SMPs in the future.

4D printing of shape memory polymers: Research status and application prospects

Shape memory polymers (SMPs) are a kind of smart material that can present active shape-changing behavior under external stimulus. Shape-changing structures based on SMPs have shown great potential to be applied in the areas ranging from aerospace to biomedicine. However, the design flexibility of such smart structures is restricted by conventional processing technique. 4D printing as the additive manufacturing technique for smart materials provides the new opportunities for the further development of SMPs. In this paper, we first reviewed the research progress about 4D printing of SMPs. Then, the investigation about the application of SMPs-based 4D structures was summarized. At last, we discussed the existing problems and further development of 4D printing of SMPs.

Progress in constitutive theory and stability research of electroactive dielectric elastomers

Dielectric elastomer has special mechanical and electrical performance. It can change its shape or volume under external electric field and can recover the original shape or volume when the electric field is removed. That makes it one of the most promising electroactive polymers for fabricating actuators, sensors, shakers and energy harvesters and have huge application potential in areas such as artificial muscle, intelligent biomimetics, aerospace, mechanics and biology. This paper make a brief review of dielectric elastomer and its applications firs and then focuses on the progress in dielectric elastomer theories, including constitutive theory, electromechanical stability, snap-through stability, giant electrostriction mechanism, allowable area description and failure analysis of dielectric devices. At last, this paper make a outlook on the research of soft dielectric electroactive elastomer.