柔性电子

Abstract(#br)Micro-transfer printing technology is rapidly emerging as an effective pathway for large-scale heterogeneous materials integration. In its basic embodiment, micro-transfer printing is used to deterministically transfer and micro-assemble prefabricated structures/devices, referred to as “ink,” from a donor substrate to a receiving substrate using a viscoelastic elastomer stamp, usually made out of polydimethylsiloxane (PDMS).

Abstract(#br)Carbon nanotubes (CNTs) based flexible films have great potential on the flexible electronics due to their relatively uniform electrical properties in the film and ease of fabrication technology. In this work, CNT/polydimethylsiloxane (PDMS) composite films with various film thickness was fabricated successfully. By introducing a percolation network model, this work reveals theoretically that the observed rapidly drops of conductivity in thin films mainly depends on the change of CNT network morphology during spin coating.

Flexible optoelectronics based on inorganic functional components have attracted worldwide attention due to their inherent advantages. However, the power supply problem presents a significant obstacle to the commercialization of wearable optoelectronics. Triboelectric nanogenerator (TENG) technology has the potential to realize self-powered applications compared to the conventional charging technologies. Herein, a flexible self-powered blood oxygen monitoring system based on TENG was first demonstrated.

Abstract(#br)Hypothesis(#br)Selective ozone treatment of Polydimethylsiloxane (PDMS) print-stamps may facilitate local de-wetting of Krytox®1506 oil; the resulting printed pattern can be used as a masking liquid during roll-to-roll vacuum-metallization, exemplified with Ag.

Abstract(#br)Hypothesis(#br)Controlling the wetting behaviour of gallium-based liquid metal is highly desired for soft electronics applications. Currently, achieving durable and patternable liquid-metal-repellent surfaces by a simple and flexible method is challenging. The femtosecond laser has a remarkable ability to modify the morphology and wettability of a solid surface.

聚二甲基硅氧烷( PDMS )具有高弹性、优良的光学特性、良好的生物相容性和稳定性，是临床柔性电子基板和封装的良好选择。本研究再次采用乳液聚合技术制备多孔PDMS，以保证汗液通过柔性电子的渗透，从而减少柔性电子对皮肤的刺激性。为了评估含湿柔性电子的力学性能，实验测量了不同相对湿度分数多孔PDMS的饱和湿浓度、湿膨胀系数和弹性模量。同时，采用渐近均匀化方法( AHM )对这些参数进行理论预测。结果表明，饱和含水率与孔隙率呈线性关系，而水分膨胀系数与孔隙率无关，两者均得到了实验数据的验证。根据实验数据，建立了考虑相对湿润率的不同孔隙率弹性模量的拟合公式。这3个参数最终应用于湿环境下蛇形互连柔性电子的拉伸性能计算。数值模拟揭示，拉伸性能随基体孔隙率和相对湿度分数以及封装程度的增加而增加。本工作希望能为柔性电子在临床应用中铺平道路。

柔性透明衬底上二维( 2D )量子材料(如MoS2、WSe2 )的直接合成、大规模集成和图形化是柔性共形器件应用的研究热点。然而，普通气相合成方法中新兴的2D材料的生长温度(如850℃)远远超出了柔性衬底(如聚二甲基硅氧烷( PDMS ) )的容限。此外，大多数生长系统中的随机成核和生长过程限制了所预测的集成和模式自由。在这里，我们报道了一种快速的直接激光结晶和无掩模大规模的MoS2和WSe2晶体在PDMS衬底上的图形化。首先通过脉冲激光沉积( PLD )系统在柔性衬底上沉积一层化学计量比非晶态2D薄膜，然后利用可调谐纳秒激光( 1064nm )控制结晶和直接写入过程。讨论了脉冲宽度、脉冲个数、沉积非晶2D层厚度对2D材料结晶的影响。通过光学光谱和电学表征证实了柔性衬底上结晶的二维材料的质量。这种新方法为未来基于二维材料的可穿戴、透明和柔性设备的计算机辅助设计模型直接结晶复杂图案开辟了新的机会。

柔性电子材料以其良好的柔性、低成本、多功能和可拆卸性等前所未有的优点，在各种应用中受到了广泛的关注，同时又不影响其电子性能。本文采用由聚二甲基硅氧烷( PDMS )和导电油墨(石墨或Ag )组成的导电材料，既保持了油墨的导电性，又提高了PDMS的疏水性和导电油墨的粘合性。为了进一步促进该材料在各种应用中的实现，提出并提出了两种新的制备方法，即塑料薄膜掩膜印刷( PFMP )和线切割放电切割( WEDC )，利用了未来在操作方便、低成本和高分辨率等方面的使用。此外，应用2D / 3D纸基柔性电路、超级电容器和3D PDMS导电模型进一步提供该材料的示范性应用，并分别在纸基和PDMS基器件上用介电电泳( DEP )分离纸上的血浆和溶液中的聚苯乙烯( PS )微球。我们相信，所提出的导电材料和制备方法满足了科学研究的需要，将为未来柔性电子、片上实验室( LOC )和生物医学领域提供新的方向。

采用超音速团束沉积( SCBD )技术将金纳米颗粒沉积到聚二甲基硅氧烷( PDMS )上，然后飞秒( fs )激光加工，制备了柔性微电极。金纳米粒子在PDMS中的SCBD形成了类似于弹性体基底的力学性能的纳米复合薄膜。电中性金属纳米粒子穿透聚合物基体，随机分布到几百纳米的深度，形成欧姆导电通路。在软基底上进行高分辨率的图形化是飞秒激光烧蚀热损伤相对很小的微米线所克服的一大挑战。制备了宽度为3   μ m的微电极。100   nm厚膜的印刷线材电阻为480 Ohm / square，200   nm厚膜的印刷线材电阻为210 Ohm / square。计算得到的薄膜平均电阻率为2.5 ~ 2.6mΩ · cm，比物理气相沉积金的平均电阻率高3个数量级，不适合用于大电流互连，但足以用于低电流信号传输，如用于电学和电化学生物传感器。