Microfluidic devices bring new opportunities in vast applications, in which the temperature control of nanoliter droplets is often required. Due to the inherit size of employed miniature volumes, several challenges exist related to temperature measurements. In this work, we present a non-contact and label-free dielectric-based temperature measurement technique. A capacitive sensor transduces the temperature-dependent dielectric properties into a capacitive value. With a post-processing tuned matching network, the reflection coefficient of the capacitive sensor is minimized at a specific frequency that is directly related to the sample temperature. The system was calibrated with a water-only calibration method using two calibration values. A measurement accuracy of ±0.24°C was achieved with an offset of -0.19°C in a temperature range from 20°C to 55°C. The possibility to use the proposed sensor as a microwave heater at the same time, can lead to a dual-purpose device that minimizes the footprint of the chip and thus its cost, while also reducing the amount of electrical connections to the chip.

中文翻译：

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具有后处理调谐匹配网络的纳升水样的基于电介质的温度传感

微流体设备在广泛的应用中带来了新的机会，其中通常需要对纳升液滴进行温度控制。由于采用的微型体积的继承大小，存在与温度测量相关的几个挑战。在这项工作中，我们提出了一种非接触式和无标签的基于电介质的温度测量技术。电容式传感器将与温度相关的介电特性转换为电容值。通过后处理调谐匹配网络，电容传感器的反射系数在与样品温度直接相关的特定频率下被最小化。该系统使用两个校准值通过纯水校准方法进行校准。在偏移为 -0 的情况下实现了 ±0.24°C 的测量精度。在 20°C 至 55°C 的温度范围内为 19°C。将所提出的传感器同时用作微波加热器的可能性可以产生一种两用设备，最大限度地减少芯片的占用空间，从而最大限度地减少其成本，同时还减少了与芯片的电连接量。