Preparation And Performance Evaluation Of The Flexible Sensor Based On Polyaniline

Flexible biosensors are generally composed of conductive materials and flexible materials.Compared with traditional sensors,flexible biosensors can better fit with human body,combining with wearable or portable biological detection devices.Polyaniline is one of the most commonly used conductive polymers with good conductivity and biocompatibility.However,the poor solubility and meltability make it difficult to process and limit its application.The effective combination of polyaniline and flexible materials in an appropriate way is the key problem in the preparation of polyaniline flexible sensors.In this paper,based on polyaniline nanoparticles,flexible electrodes were prepared by electrospinning and 3D printing,and the properties of the electrodes were investigated.The study was divided into three parts.In the first part,polyaniline nanoparticles with particle size of about 100 nm and good conductivity were synthesized by microemulsion method.In the second part,composite pH sensitive electrode films with good electrochemical response were developed by coaxial electrospinning of polyaniline(PANI)and polyurethane(PU)into core-shell fibers.PU improves the strength of the films.The mechanical properties and impedance properties are closely related to the proportion of PANI and PU in the films,and the films have wide space for the designing the properties and applications.By chronopotentiometry in buffer solutions,the film electrode works linearly in the pH range of 2?7 with the sensitivity of-60.5m V/pH and pH changes below 0.2 can be detected.It was also proved that the film electrode can detect pH stably and have a response to the pH of small amount of sweat on the skin,which suggested the possibility in wearable devices.In the third part,the flexible electrode was prepared by printing polyaniline ink on polyurethane fiber film by 3D printing.The sensitivity of the 3D print electrode to pH was-50.3 m V/pH in the acidic range.Conclusion: Electrodes with good mechanical properties and detection properties can be obtained by combining polyaniline nanoparticles with elastic polymer polyurethane by coaxial electrospinning and 3D printing,further promising an application prospect in biological detection.