The ever-increasing number of devices on wearable and portable systems comes with challenges such as integration complexity, higher power requirements, and less user comfort. In this regard, the development of multifunctional devices could help immensely as they will provide the same functionalities with lesser number of devices. Herein, we present a dual-function flexible loop antenna printed on polyvinyl chloride (PVC) substrate. With a poly(3,4-ethylenedioxythiophene): polystyrene (PEDOT:PSS) section as part of the printed structure, the presented antenna can also serve as a temperature sensor by means of change in resistance. The antenna resonates at 1.2- and 5.8-GHz frequencies. The ohmic resistance of the temperature sensing part decreases by ~70% when the temperature increases from 25 °C to 90 °C. The developed antenna was characterized using a vector network analyzer (VNA) in the same temperature range and the S11 magnitude was found to change by ~3.5 dB. The induced current was also measured in the GSM frequency range and sensitivity of ~1.2%/°C was observed for the sensing antenna. The flexible antenna was also evaluated in lateral and cross-bending conditions and the response was found to be stable for the cross-bending. Due to these unique features, the presented antenna sensor could play a vital role in the drive toward ubiquitous sensing through wearables, smart labels, and the Internet of Things (IoT).

中文翻译：

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印刷无芯片天线作为柔性温度传感器

可穿戴和便携式系统上设备的数量不断增加，带来了诸如集成复杂性，更高的电源要求以及用户舒适度降低等挑战。在这方面，多功能设备的开发可能会提供极大的帮助，因为它们将以更少的设备数量提供相同的功能。在这里，我们提出了一种印在聚氯乙烯（PVC）基板上的双功能柔性环形天线。将聚（3,4-乙撑二氧噻吩）：聚苯乙烯（PEDOT：PSS）部分作为印刷结构的一部分，所提供的天线还可以通过电阻变化用作温度传感器。天线在1.2 GHz和5.8 GHz频率下谐振。当温度从25°C升高到90°C时，温度感应部件的欧姆电阻降低约70％。使用矢量网络分析仪（VNA）在相同温度范围内对开发的天线进行了表征，发现S11幅度变化了〜3.5 dB。还在GSM频率范围内测量了感应电流，并且感应天线的灵敏度约为〜1.2％/°C。还在横向和横向弯曲条件下评估了柔性天线，发现响应对于横向弯曲是稳定的。由于这些独特的功能，提出的天线传感器在通过可穿戴设备，智能标签和物联网（IoT）进行无处不在的传感的过程中可能起着至关重要的作用。对于感应天线，观察到2％/°C。还在横向和横向弯曲条件下评估了柔性天线，发现响应对于横向弯曲是稳定的。由于这些独特的功能，提出的天线传感器在通过可穿戴设备，智能标签和物联网（IoT）进行无处不在的传感的过程中可能起着至关重要的作用。对于感应天线，观察到2％/°C。还在横向和横向弯曲条件下评估了柔性天线，发现响应对于横向弯曲是稳定的。由于这些独特的功能，提出的天线传感器在通过可穿戴设备，智能标签和物联网（IoT）进行无处不在的传感的过程中可能起着至关重要的作用。