Ortega-Santos Amaia B, Martínez Jose G, Jager Edwin W H
Sensor and Actuator Systems, Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden.
Chem Mater. 2024 Sep 30;36(19):9391-9405. doi: 10.1021/acs.chemmater.4c00873. eCollection 2024 Oct 8.
Conducting polymers (CP) have shown great features in building textile actuators. To date, most of the yarn-based or CP-yarn actuators have been operated in liquid electrolytes in a three-electrode-cell configuration, comprising an external counter and a reference electrode. For integration in textiles, a two-electrode system is needed, where both electrodes are in a yarn format. This can be achieved by having two CP-yarns, where one acts as the anode and the other as the cathode. For these two CP-yarns to operate synchronically, they both need to expand (or contract) during opposite reactions. This can be achieved by doping one CP-yarn with mobile anions that will expand during oxidation, while the other CP-yarn should be doped with immobile anions expanding during reduction. As a result, the same movement is created upon opposite redox reactions, both collaborating with the actuation in the same direction without the need for an external passive electrode to close the electrical circuit, which could oppose or hinder the movement. Most of the studies on textile actuators are based on cation-driven CP-yarn actuators, while little is known about anion-driven systems in CP-yarn actuators. Here, we first present a study of the effect of the dopants, solvents, and polymer layer combinations on the mechanism and strain of CP-yarns. The CP-yarns are coated with two layers: an inner poly(3,4-ethylenedioxythiophene) (PEDOT) layer and the outer and active polypyrrole (PPy) layer. According to our results, the dopant of the inner PEDOT layer seems to affect the actuation mechanism of the outer PPy layer and, thereby, of the whole CP-yarn actuator, influencing the direction of the movement and enhancing or hindering the total strain of the actuator. We show that a CP-yarn coated with PEDOT(Tos)/PPy(ClO) and actuated in LiClO aqueous solution showed a pure anion-driven actuation. Next, based on the latter results, we demonstrate for the first time the dual actuation of two CP-yarns, doped with two different dopants, ClO and DBS, actuating simultaneously driven by opposite redox reactions and exhibiting an average of 0.5% of strain, an important step toward in-air actuating yarns.
导电聚合物（CP）在构建纺织致动器方面展现出了卓越特性。迄今为止，大多数基于纱线的或CP纱线致动器都是在三电极电池配置的液体电解质中运行，该配置包含一个外部对电极和一个参比电极。为了集成到纺织品中，需要一个双电极系统，其中两个电极均为纱线形式。这可以通过使用两根CP纱线来实现，一根作为阳极，另一根作为阴极。为了使这两根CP纱线同步运行，它们在相反反应过程中都需要膨胀（或收缩）。这可以通过用在氧化过程中会膨胀的可移动阴离子掺杂一根CP纱线来实现，而另一根CP纱线则应掺杂在还原过程中膨胀的不可移动阴离子。结果，在相反的氧化还原反应中会产生相同的运动，两者在相同方向上协同致动，无需外部无源电极来闭合电路，因为外部无源电极可能会阻碍运动。大多数关于纺织致动器的研究都基于阳离子驱动的CP纱线致动器，而对于CP纱线致动器中的阴离子驱动系统了解甚少。在此，我们首先展示了一项关于掺杂剂、溶剂和聚合物层组合对CP纱线的机理和应变影响的研究。CP纱线涂有两层：内层的聚（3,4 - 亚乙基二氧噻吩）（PEDOT）层和外层的活性聚吡咯（PPy）层。根据我们的结果，内层PEDOT层的掺杂剂似乎会影响外层PPy层的致动机理，进而影响整个CP纱线致动器的致动机理，影响运动方向并增强或阻碍致动器的总应变。我们表明，涂有PEDOT(Tos)/PPy(ClO)并在LiClO水溶液中致动的CP纱线表现出纯阴离子驱动的致动。接下来，基于后者的结果，我们首次展示了两根掺杂有两种不同掺杂剂ClO 和DBS的CP纱线的双致动，它们在相反的氧化还原反应驱动下同时致动，平均应变达0.5%，这是迈向空气中致动纱线的重要一步。
