Polymer-liquid crystals (PLC) is a common material for smart windows. However, PLC smart windows usually require high driving voltage to maintain transparency. In this work, we synthesized a novel PLC smart film by doping multi-wall carbon nanotubes (MWCNT) into a reverse-mode polymer network liquid crystal (R-PNLC). It was found that doping MWCNT could effectively reduce the threshold voltage (Vth) of R-PNLC from 19.0V to 8.4V. Due to co-orientation between MWCNT and LC molecules, the doped R-PNLC was able to maintain a high transmittance of visible light (~80%) without an applied electric field. We found that doping MWCNT could change the frequency modulation property of R-PNLC. The doped R-PNLC exhibits a wider frequency modulation range up to 40,000Hz, while the frequency modulation of the undoped R-PNLC reached to a saturation at 23,000 Hz. We also tested the electromagnetic interference (EMI) shielding efficiency of R-PNLC and found that the EMI shielding efficiency could be improved by doping only 0.01wt% MWCNT into the system. The total shielding effectiveness (SET) value of 0.01wt% MWCNT doped R-PNLC was up to 14.91 dB during frequency band of 5.38 GHz-8.17 GHz. This study demonstrates that the films are potentially useful for low-energy-consumption smart windows with enhanced electromagnetic shielding capability.
Untethered capsules hold clinical potential for the diagnosis and treatment of gastrointestinal diseases. Although considerable progress has been achieved recently in this field, the constraints imposed by the narrow spatial structure of the capsule and complex gastrointestinal tract environment cause many open-ended problems, such as poor active motion and limited medical functions. In this work, we describe the development of small-scale magnetically driven capsules with a distinct magnetic soft valve made of dual-layer ferromagnetic soft composite films. A core technological advancement achieved is the flexible opening and closing of the magnetic soft valve by using the competitive interactions between magnetic gradient force and magnetic torque, laying the foundation for the functional integration of both drug release and sampling. Meanwhile, we propose a magnetic actuation strategy based on multi-frequency response control and demonstrate that it can achieve effective decoupled regulation of the capsule’s global motion and local responses. Finally, through a comprehensive approach encompassing ideal models, animal ex vivo models, and in vivo assessment, we demonstrate the versatility of the developed magnetic capsules and their multiple potential applications in the biomedical field, such as targeted drug delivery and sampling, selective dual-drug release, and light/thermal-assisted therapy.