电磁干扰（EMI）的存在会导致电流和电压波形失真，从而降低传感器设备的精度和稳定性。柔性电子设备的出现打破了物理空间的限制，可以随意弯曲和扭曲，这一特性加剧了其内部传感元件之间不必要的耦合，从而导致相互干扰。目前，解决电磁干扰的方法主要是采用电磁屏蔽（EMS），但仅靠这种方法无法解决柔性传感器件内部EMI。
近日，中国科学院理化技术研究所邓中山教授和李雷副研究员等人在Science China Materials发表研究论文，将镓基液态金属（LM）电路印制在Ecoflex@Fe薄膜上，设计出兼具EMS和吸波功能的可拉伸电磁波屏蔽和吸收（EWSA）薄膜，可有效解决内部和外部EMI的影响。
本文要点
1) EWSA薄膜一侧的屏蔽效能高达54.5 dB，而另一侧的反射损耗则低至−43.5dB。2) 基于LM的EWSA薄膜在不同方向的拉伸过程中都能保持良好的EMS和吸波性能，在拉伸1000次后还能有效避免EMI。总之，基于LM的EWSA薄膜实现了宽频带的EMS和吸波功能，为开发能够消除内部和外部EMI的新一代柔性电子皮肤提供了解决方案。Figure 1. The LM-based EWSA film capable of stretchability, EMS and wave absorption.Figure 2. Preparation process and morphological characterizations of LM-based EWSA film. (a) Process for the preparation of Ecoflex@Fe films with one nonporous side and one porous side. (b) LM circuits were first printed on the intermediate and bottom films, followed by spin-coating of pure Ecoflex (1 g) on the three films in sequence. (c) Ecoflex@Fe films, all spin-coated with 1 g of pure Ecoflex, were stacked sequentially with the porous side facing up. After heating in the oven for 10 min, the EWSA film is obtained. (d) Overlapping EDS elemental map of silicon (Si) and gallium (Ga) in the EWSA film. (e) SEM image of the EWSA film.![]()
Figure 3. EMS properties of the LM-based EWSA film. (a) SE at 1:1 circuit spacing with 1, 2 or 3 mm circuit width distribution. (b) Test environment for vector network instrumentation. (c) Viewing angle when the LM circuits of the bottom film are at 0°, 45°, 90°, and 135° from the horizontal line. (d) SE of the EWSA film when the LM circuits of the bottom film are at 0°, 45°, 90°, and 135° from the horizontal line. (e) SE at 0%, 20%, 50%, and 100% stretching of the EWSA film when the circuit spacing is 1:1 and the width is 2 mm. (f) SE of the EWSA film after stretching 1000 times in any direction.![]()
Figure 4. Wave-absorbing properties of the LM-based EWSA film. (a) Reflectivity corresponding to circuit widths of 1, 2 and 3 mm at 1:1 spacing. (b) Reflectivity corresponding to circuit spacing of 1:0.5, 1:1 and 1:1.5 for a circuit width of 2 mm. (c) Reflectivity of the EWSA film when the LM circuits of the bottom film are at 0°, 45°, 90°, and 135° from the horizontal line. (d) Reflectivity of EWSA film stretched to 0%, 20%, 50% and 100%, when the circuit pitch is 1:1 and the width is 2 mm. (e) Reflectivity of EWSA film after stretching 1000 times in any direction. (f) SE and reflectance corresponding to the EWSA film without LM circuits and with LM circuits of 2-mm width and 1:1 pitch.Xilong Zhang, Zhongshan Deng, Huize Song, Minghui Guo, Lei Li. Liquid metal electromagnetic wave shielding and absorbing film for solving electromagnetic interference in flexible sensors. Sci. China Mater. (2024).https://doi.org/10.1007/s40843-024-3111-2
![]()
点击左下角“阅读原文”，阅读以上文章PDF原文
![]()
