We report the performance of stretchable sensors for the NO₂ detection, which were fabricated by depositing multi-walled carbon nanotubes (MWCNTs)/CeO₂ composites on a silicon rubber. SEM images of the sensor’s surface revealed that the MWCNTs are interconnected forming long carbon fibers, while the CeO₂ powders consisted in a mixture of nanorods and porous coalesced nanoparticles. The detection tests for the NO₂ gas were carried out by using sensors stretched at 0%, 50% and 100% strain. The best performance for the NO₂ detection (1, 100 and 1000 ppm) was observed for the sensor stretched at 100% strain, since it produced a detection response ≈ 3.25 times faster than that for the non-stretched sensor (0% strain). Moreover, the sensor elongated up to 100% strain presented the lowest response and recovery times of 25.6 and 383.9 s, respectively. The improvement of the detection response and the reduction of the response/recovery times were caused by the increase of the oxygen vacancy defects (active sites for the adsorption of NO₂ molecules) on the sensor’s surface when the tensile strain is applied. The presence of these defects was confirmed by Raman, XPS and absorbance measurements. Additionally, MWCNTs/CeO₂ composites were deposited on a jelly based substrate to construct a flexible and biodegradable sensor. Interestingly, this device had even lower response/recovery times (22.9/345.2 s) than the stretchable sensors for the detection of NO₂ (100 ppm). The response times for the stretchable/biodegradable sensors are among the lowest reported so far and the sensors operate at low energy consumption (50–67 µW).

我们报告了用于 NO ₂检测的可拉伸传感器的性能，该传感器是通过在硅橡胶上沉积多壁碳纳米管 (MWCNT)/CeO _{2复合材料制成的。}传感器表面的 SEM 图像显示，MWCNT 相互连接形成长碳纤维，而 CeO ₂粉末由纳米棒和多孔聚结纳米颗粒的混合物组成。_{NO 2}气体的检测试验通过使用在0%、50%和100%应变下拉伸的传感器进行。_{NO 2}的最佳表现对于在 100% 应变下拉伸的传感器，观察到检测（1、100 和 1000 ppm），因为它产生的检测响应比未拉伸传感器（0% 应变）快 3.25 倍。此外，拉长至 100% 应变的传感器呈现出最低的响应和恢复时间，分别为 25.6 和 383.9 秒。检测响应的提高和响应/恢复时间的减少是由于施加拉伸应变时传感器表面的氧空位缺陷（NO _{2分子吸附的活性位点）增加所致。}这些缺陷的存在通过拉曼、XPS 和吸光度测量得到证实。此外，MWCNTs/CeO ₂将复合材料沉积在基于果冻的基板上，以构建灵活且可生物降解的传感器。有趣的是，该设备的响应/恢复时间 (22.9/345.2 s) 甚至比用于检测 NO ₂ (100 ppm) 的可拉伸传感器还要短。可拉伸/可生物降解传感器的响应时间是迄今为止报告的最低值之一，并且传感器以低能耗 (50–67 µW) 运行。