杂货铺科学（20220331）通过类似于quipu的硅胶-液态金属压力传感器进行低成本胃肠测压
杂货铺指数：❤❤❤❤❤
（an overall device cost of less than US$0.26 per centimetre. 1块五每厘米）
打结处为什么对压力变化更敏感？
We speculated two reasons for the enhanced pressure sensitivity due to knotting. First, the process increased the aspect ratio of the catheter cross-section due to shear stress, which made it more sensitive to deformations than the unknotted case under the same loading conditions. Second, similar to serially connected springs, each catheter layer that was folded and stacked onto itself due to knotting experienced the same external pressure component perpendicular to the stacking plane, resulting in an amplification of the effective total pressure. （我们推测由于打结而增强压力敏感性的两个原因。 首先，由于剪切应力，该过程增加了导管横截面的纵横比，这使其在相同载荷条件下比未打结的情况下对变形更敏感。 其次，类似于串联弹簧，由于打结而折叠并堆叠到自身上的每个导管层都经历了垂直于堆叠平面的相同外部压力分量，从而导致有效总压力的放大。）
真结绳记事.Quipu（也拼写为 khipu）是一种记录设备，由历史上在南美洲安第斯山脉地区的许多文化中使用绳制成。
花絮：据悉作者因为疫情不能去实验室做实验，只好带上简陋的设备买简单材料居家卷。在条件受限的情况下开创动脑筋创造了低成本测压的新途径。赞！
液态金属：
11. Dickey, M. D. et al. Eutectic gallium‐indium (EGaIn): a liquid metal alloy for the formation of stable structures in microchannels at room temperature. Adv. Funct. Mater. 18, 1097–1104 (2008).
12. Cooper, C. B. et al. Stretchable capacitive sensors of torsion, strain, and touch using double helix liquid metal fibers. Adv. Funct. Mater. 27, 1605630 (2017).
13. Yeo, J. C., Yu, J., Koh, Z. M., Wang, Z. & Lim, C. T. Wearable tactile sensor based on flexible microfluidics. Lab Chip 16, 3244–3250 (2016).
14. Gao, Y. et al. Wearable microfluidic diaphragm pressure sensor for health and tactile touch monitoring. Adv. Mater. 29, 1701985 (2017).
15. Ma, Z. et al. Permeable superelastic liquid-metal fibre mat enables biocompatible and monolithic stretchable electronics. Nat. Mater. 20, 859–868 (2021)
