This paper reports on the controlled fabrication of a highly sensitive piezoresistive sensor by using Si nanorod (NR) arrays. An efficient, large-area, scalable strategy was adopted to fabricate the pressure sensors by incorporating chemically etched, high-aspect-ratio, vertical Si NR arrays between two thin Au layers. The piezoresistive properties corresponding to dimension- and position-controlled and randomly etched, closely packed, and thin Si NR arrays were exploited to fabricate the small, portable, and device-compatible pressure sensors. The Si-NR-based piezoresistive sensors exhibited a high sensitivity of 0.49 MPa⁻¹, thereby demonstrating its superiority over other unconventional piezoresistive nanomaterials such as Si with different configurations of nanostructures. Furthermore, the sensors exhibited a large variation (~45%) in the current at a constant bias voltage of 2 V under a weak applied pressure corresponding to an inert gas flow of 5 sccm. The excellent pressure sensing performance of the piezoresistive Si NRs enabled the efficient detection of changes corresponding to the human breathing pattern. In particular, the key advantages of such pressure sensors is the simple, inexpensive, and scalable fabrication process; high sensitivity with ultra-low-pressure detection; and excellent ambient stability (>several months) with a high durability pertaining to more than 1,000 cycles of pressure loading/unloading. Furthermore, we demonstrated the ability of the pressure sensor to act as a portable human breath sensor to monitor respiratory parameters in a noninvasive and personalized manner. The results can provide direction for the realization of next-generation breath-sensing gadgets and other leading-edge applications in the domain of electronic and healthcare devices.

本文报道了通过使用Si纳米棒（NR）阵列控制制造高灵敏度压阻传感器的过程。通过在两个薄的Au层之间合并化学蚀刻的高纵横比垂直Si NR阵列，采用了一种有效的，大面积，可扩展的策略来制造压力传感器。利用与尺寸和位置控制以及随机蚀刻，紧密堆积的薄Si NR阵列相对应的压阻特性来制造小型，便携式且与设备兼容的压力传感器。基于Si-NR的压阻传感器表现出0.49 MPa ^-1的高灵敏度，从而证明了其相对于其他非常规压阻纳米材料（例如具有不同纳米结构构型的Si）的优越性。此外，在对应于5 sccm惰性气体的弱施加压力下，传感器在2 V的恒定偏置电压下电流表现出较大的变化（〜45％）。压阻Si NR的出色压力感测性能可有效检测与人类呼吸模式相对应的变化。特别地，这种压力传感器的主要优点是简单，便宜且可扩展的制造过程；高灵敏度，超低压检测；出色的环境稳定性（大于数月），以及与1,000次以上的压力加载/卸载循环有关的高耐久性。此外，我们证明了压力传感器可以充当便携式人类呼吸传感器来以无创且个性化的方式监测呼吸参数的能力。这些结果可为实现下一代呼吸感应小工具以及电子和医疗保健设备领域中的其他前沿应用程序提供指导。