The advent of high frequency communication era presents new challenges for further development of dielectric polymer materials. In the field of communication, efficient signal transmission is critical. The lower the dielectric constant of the dielectric material used, the lower the signal delay and the higher the signal fidelity. The preparation of polymer materials with low dielectric constant or reduce the dielectric constant of polymer materials becomes a key research topic. Summarizing past progress and providing perspective, this paper primarily discusses the intrinsic low dielectric polymers, fluorine doped low dielectric polymers, and microporous low dielectric polymers, while predicting the research trend of low dielectric materials.

To eliminate the negative effect of traditional metal-working fluids and achieve sustainable manufacturing, the usage of nano-enhanced biolubricant (NEBL) is widely researched in minimum quantify lubrication (MQL) machining. It’s improved tool wear and surface integrity have been preliminarily verified by experimental studies. The previous review papers also concluded the major influencing factors of processability including nano-enhancer and lubricant types, NEBL concentration, micro droplet size, and so on. Nevertheless, the complex action of NEBL, from preparation, atomization, infiltration to heat transfer and anti-friction, is indistinct which limits preparation of process specifications and popularity in factories. Especially in the complex machining process, in-depth understanding is difficult and meaningful. To fill this gap, this paper concentrates on the comprehensive quantitative assessment of processability based on tribological, thermal, and machined surface quality aspects for NEBL application in turning, milling, and grinding. Then it attempts to answer mechanisms systematically considering multi-factor influence of molecular structure, physicochemical properties, concentration, and dispersion. Firstly, this paper reveals advanced lubrication and heat transfer mechanisms of NEBL by quantitative comparison with biolubricant-based MQL machining. Secondly, the distinctive filmformation, atomization, and infiltration mechanisms of NEBL, as distinguished from metal-working fluid, are clarified combining with its unique molecular structure and physical properties. Furtherly, the process optimization strategy is concluded based on the synergistic relationship analysis among process variables, physicochemical properties, machining mechanisms, and performance of NEBL. Finally, the future development directions are put forward aiming at current performance limitations of NEBL, which requires improvement on preparation and jet methods respects. This paper will help scientists deeply understand effective mechanism, formulate process specifications, and find future development trend of this technology.

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To meet the demands of multifunctional applications, developing functional composites with excellent properties (such as high dielectric permittivity, good mechanical properties, and anisotropic optical transmittance) is urgent. In this regard, preparing composites with all‐organic components is a promising strategy. Herein, we demonstrated a simple and time‐saving method for assembling and aligning polyaniline (PANI) particles in the TPU matrix by an AC electric field. The alignment of PANI in the polymer matrix not only obviously enhances dielectric permittivity but also effectively increases optical anisotropy. At the same filler loading content, the dielectric permittivity of aligned composites prepared under 10 Hz electric fields is 10.63 (10−1 Hz), which is higher than the dielectric property of random composites (8.58). The kinetics of aligning process of PANI particles are systematically studied by in situ optical microscope while an AC electric field is applied. We believe that this research work provides a potential solution to increase both dielectric permittivity and optical anisotropy of composites by the alignment of organic fillers via an electric field, which is essential for future flexible wearable electronics.

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