Lin Tong-Hong, Su Wenjing, Cui Yepu, Bahr Ryan, Tentzeris Manos M
Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, 30332-250, USA.
Sci Rep. 2024 Aug 1;14(1):17787. doi: 10.1038/s41598-024-68616-z.
Fluid sensing has been an important but missing part of the massive Internet-of-Things sensor networks due to challenges including excessive manufacturing time/cost, finite wireless interrogation range, limited immunity to ambient clutter, and excessive required power for autonomous microfluidics operability. Here, we proposed an additive manufacturing flexible system as a solution to those challenges while enabling fluid analysis from controlled labs to virtually everywhere. Energy harvesting provides all required power for the actuation of the micro-pump enabling battery-less liquid sample acquisition. Energy sources including ultra-high-frequency radio frequency identification and hand-held devices like two-way talk radio are harvested simultaneously to support energy requirements for periodic monitoring every 6.6 min and on-demand monitoring within 4.63 s. Backscattering topologies are used to significantly extend the reading range while increasing the immunity to interferences and reducing the cost to the reader. A new additive manufacturing process is proposed to reduce fabrication time and cost while enabling massive scalability of flexible microfluidics. The good flexibility makes the system suitable for working toward future wearable applications. Prototypes of a sweat sensing system are demonstrated and successfully interrogated at 3 m with more than 15 dB signal-to-noise ratio using only a 14 dBm transmitter equivalent isotropic radiated power.
由于存在诸多挑战，包括制造时间/成本过高、无线询问范围有限、对环境杂波的抗干扰能力有限以及自主微流体操作所需功率过大等，流体传感一直是大规模物联网传感器网络中一个重要但缺失的部分。在此，我们提出了一种增材制造柔性系统，作为应对这些挑战的解决方案，同时实现从受控实验室到几乎任何地方的流体分析。能量收集为微型泵的驱动提供了所有所需的电力，从而实现无电池液体样本采集。同时收集包括超高频射频识别和双向对讲机等手持设备在内的能源，以满足每6.6分钟进行一次定期监测以及在4.63秒内进行按需监测的能源需求。反向散射拓扑结构用于显著扩展读取范围，同时提高抗干扰能力并降低读取器成本。我们提出了一种新的增材制造工艺，以减少制造时间和成本，同时实现柔性微流体的大规模可扩展性。良好的柔韧性使该系统适用于未来的可穿戴应用。展示了一种汗液传感系统的原型，并仅使用14 dBm发射机等效全向辐射功率在3米处成功进行了询问，信噪比超过15 dB。
