高导电性、可回收和抗菌的物理交联聚乙烯醇/壳聚糖-植酸水凝胶用于可穿戴传感器

Physically crosslinked polyvinyl alcohol/chitosan-phytic acid hydrogels for wearable sensors with highly conductive,recyclable and antibacterial properties

导电水凝胶作为可穿戴式传感器满足了机械灵活性和智能感应的基本要求.然而,它们往往遇到一些问题,如良好的机械性能和高导电性之间的不相容性、较差的抗菌能力和难以回收.在此,我们通过简单的冻融方法开发了高导电性物理交联的聚乙烯醇/壳聚糖-植酸(PVA/CS-PA)水凝胶.PA与CS和PVA基质之间的氢键和静电作用不仅赋予了水凝胶适宜的机械性能和良好的延展性,而且还使其具备有意义的可回收特性.此外,由于PA分子的离子传导性和抗菌能力,该水凝胶表现出卓越的导电性(~0.125 S cm^(-1))和抗菌活性.这些特殊的性能使基于该水凝胶的可穿戴传感器表现出应变敏感的特性(在200%-420%的应变下,应变系数为7.21),可以监测人体的各种活动.此外,PVA/CSPA溶胶墨水可以在冰浴环境下转变为凝胶状态,这将满足柔性电路的需要,并使可穿戴式传感器更加便携.

Conductive hydrogels as wearable sensors meet the basic requirements of mechanical flexibility and intelligent sensing.However,they are often hampered by problems such as the incompatibility between favorable mechanical properties and high conductivity,inferior antimicrobial ability and difficulty in recycling.Herein,highly conductive and physically cross-linked polyvinyl alcohol/chitosan-phytic acid(PVA/CS-PA)hydrogels were developed by a facile freezethaw method.The hydrogen bonding and electrostatic interaction between PA and matrix of CS and PVA endow hydrogels with not only moderate mechanical properties and high degree of ductility,but also meaningfully recyclable characteristics.In addition,the hydrogel exhibits superior conductivity(~0.125 S cm^(-1))and antimicrobial activity,benefiting from the ionic conductivity and antibacterial capacity of PA molecules.These exceptional properties enable the hydrogel-based wearable sensors to exhibit strain-sensitive properties(a gauge factor of 7.21 under strains of 200%-420%),which could monitor various activities of human body.More interestingly,the PVA/CS-PA sol ink could be transformed into a gel state in an ice bath,which would meet the need of flexible circuit and make wearable sensors more portable.