Abstract

Nowadays, great effort has been devoted to fabricate flexible wearable sensor with high stretchability, moderate modulus, favorable durability, excellent transparency, and satisfactory sensitivity. In this work, we report the preparation of a hybrid double-network (DN) hydrogel by a simple one-pot method. First, chitosan was added into an AlCl₃ solution to form Al³⁺-chitosan complex (CS-Al³⁺). Second, the hybrid CS/Al³⁺-poly(acrylamide) (PAM) DN hydrogels were constructed via in situ polymerization of acrylamide (AM) in present of Al³⁺-chitosan complex. Thanks to the existence of electrically conductive CS-Al³⁺ networks, the resulting hybrid DN hydrogel exhibits excellent stretchability, fatigue resistance, transparency, and conductivity. Furthermore, the CS/Al³⁺-PAM DN hydrogel could be used as strain sensor, and demonstrates many desired virtues, including satisfactory sensitivity (gauge factors of 1.7–12.1), wide detection range (up to 1500%), low limit of discernment (1% strain), high reliability, and excellent durability (1000 cycles). More significantly, the manufactured hydrogel-based strain sensor can be employed as wearable devices to precisely detect various human movements.

摘要

目前，人们致力于制造具有高拉伸性、适中模量、良好的耐久性、优异的透明度和令人满意的灵敏度的柔性可穿戴传感器。在这项工作中，我们报告了通过简单的一锅法制备混合双网络 (DN) 水凝胶。首先，将壳聚糖加入到AlCl ₃溶液中以形成Al ^{3+ -}壳聚糖复合物(CS-Al ³⁺ )。其次，通过丙烯酰胺 (AM) 在 Al ^{3+ -}壳聚糖复合物存在下的原位聚合构建了混合 CS/Al ^{3+ -}聚（丙烯酰胺）（PAM）DN 水凝胶。由于导电性 CS-Al ³⁺的存在网络，由此产生的混合 DN 水凝胶表现出优异的拉伸性、抗疲劳性、透明度和导电性。此外，CS/Al ³⁺ -PAM DN 水凝胶可用作应变传感器，并表现出许多理想的优点，包括令人满意的灵敏度（应变系数为 1.7-12.1）、检测范围广（高达 1500%）、下限识别力（1% 应变）、高可靠性和出色的耐用性（1000 次循环）。更重要的是，制造的基于水凝胶的应变传感器可以用作可穿戴设备来精确检测各种人体运动。