Annular flexible thermoelectric devices with integrated-module architecture

Organic and composite thermoelectric(TE)materials have witnessed explosive developments in recent years.Design strategy of their flexible devices is vital to achieve high performance and suit various application environments.Here,we propose a design strategy of annular flexible TE devices with integrated-module architecture,where the independent modules made up of alternatively connected p-n couples are connected in series,and then rounded head-to-tail into annular configuration.The achieved devices can not only save plenty of space owing to their highly integrated structure design,but also be directly mounted on cylindrical objects(like pipes)to suit versatile applications.More importantly,the annular TE devices display excellent performances,superior to most previous work and the traditional serial single-layer film structure.For example,the annular device with eight modules consisting of three p-n couples reveals an output power of 12.37μW at a temperature gradient of 18 K,much higher than that of the corresponding single-layer film structure(1.74μW).The integration process is simple and easy to scale up.This architecture design strategy will greatly speed up the TE applications and benefit the research of organic and composite TE materials.