一种用于可穿戴传感器的超柔性、透明、自粘附、可自愈、抗冻和长期稳定冷冻水凝胶

软体器件领域亟需多功能水凝胶,然而,其复杂的功能成分在实际应用中存在安全和环境隐患.在本研究中,单一氯化锂盐在构建冻融聚乙烯醇水凝胶的多层次结构中同时发挥多重作用,激发其前所未有的多功能性和长期稳定性.(1)在冷冻过程中,抗冻盐氯化锂抑制了冰晶的生长,由于冰晶对分子链的排异作用减弱,聚合物分子链靠近程度较弱,实现了分子链网络的非晶化及自由羟基的部分释放.(2)由于氯化锂的水合作用,自由水分子的选择性挥发不仅使高分子网络密集化,同时赋予水凝胶长期稳定性.(3)氯化锂的加入也赋予水凝胶固有特性.因此,最终所得聚乙烯醇水凝胶具备多功能性,包括卓越的柔性(杨氏模量为18.8 kPa)、延展性(704%)、透明度(84%)、粘附性、自愈性、抗冻性(-43℃)和长期稳定性(5个月后宽度和厚度分别为初始尺寸的95%和87%).本研究证明了单一冷冻水凝胶在可穿戴传感器中的应用.考虑到独特的多层次结构及多功能性,预计新一代聚乙烯醇水凝胶将为各种柔性设备提供更多的机会.

Synthesis of silicone blocked bio-polyurethane and its application in highly stretchable fiber-shaped strain sensor

Flexible strain sensors have become a key component of intelligent wearable electronics.However,the fabrication of strain sensors with wide workable strain ranges and high sensitivity remains a great challenge.Additionally,the rapid development of polymer composites based strain sensors has produced a large amount of e-waste.Therefore,the development of strain sensors with wide strain sensing ranges and high sensitivity based on degradable materials is necessary.In this work,a silicone blocked polyurethane(Si-BPU)with high stretchability and degradability was synthesized and composited with carbon nanotubes(CNTs)to fabricate fibrous strain sensors.The synthesized 0.5%Si-BPU exhibited good biodegradability with a weight loss of 16.47%in 42 days.The Si-BPU/12CNTs fiber based strain sensor achieved a sensing range of 0%–353.3%strain,gauge factor(GF)of 206.3 at 250%strain and of 4,513.2 at 353.3%strain,reliable stability under 10,000 repeated stretching–releasing cycles.Moreover,the Si-BPU/12CNTs strain sensor showed rapid response time(<163 ms)and was capable of monitoring various human body movements(elbow bending,finger bending,breath,swallow).In consequence,this work provides a new and effective strategy for the development of sustainable wearable electronic devices.

Superabsorbent Fibers for Comfortable Disposable Medical Protective Clothing

Disposable medical protective clothing for 2019-nCoV mainly consists of stacked layers with nanopore films,polymer coated nonwoven fabrics and melt-blown nonwoven fabrics against anti-microbial and anti-liquid penetration.However,such structures lack moisture permeability and breathability leading to an uncomfortable,stuffy wearing experience.Here,we propose a novel medical protective clothing material with a superabsorbent layer to enhance moisture absorption.Poly(acrylic acid-co-acrylamide)/polyvinyl alcohol superabsorbent fibers(PAAAM/PVA fibers)were prepared via wet spinning.And the superabsorbent composite layer was stacked from PAAAM/PVA fibers,bamboo pulp fibers(BPF)and ethylene-propyl-ene side by side fibers(ESF).The novel disposable medical protective composite fabric was obtained through gluing the superabsorbent layer to the inner surface of strong antistatic polypropylene nonwoven fabric.The resultant composite fabric possesses excellent absorption and retention capacity for sweat,up to 12.3 g/g and 63.8%,and a maximum hygroscopic rate of 1.04 g/h,higher than that of the conventional material(only 0.53 g/h).The moisture permeability of the novel material reached 12,638.5 g/(m^(2) d),which was 307.6%of the conventional material.The novel material can effectively reduce the humidity inside the protective clothing and significantly improve the comfort of medical staff.

Recent Progress on Smart Fiber and Textile Based Wearable Strain Sensors:Materials,Fabrications and Applications

With the rapid development of smart products,fexible and stretchable smart wearable electronic devices gradually play an important role,and they are considered as the pioneers of the new generation of fexible electronic devices.Among these intelligent devices,fexible and stretchable strain sensors have been widely studied for their good fexibility,high sensitivity,high repeatability and huge potential for application in personal healthcare and motion detection.Moreover,unlike traditional rigid bulky sensors,the high-performance fexible strain sensors are lightweight portable devices with excellent mechanical and electrical performance,which can meet personalized needs and become more popular.Herein,the research progress of fexible strain sensors in recent years are reviewed,which mainly introducing the sensing principles and key parameters of strain sensors,commonly used conductive materials and fexible substrates and common preparation methods,and fnally proposes the future application and prospects of strain sensors.

Correction to:Recent Progress on Smart Fiber and Textile Based Wearable Strain Sensors:Materials,Fabrications and Applications

Correction to:Advanced Fiber Materials https://doi.org/10.1007/s42765-021-00126-3 Due to an unfortunate oversight during the e.proofng process Jinlei Miao has not been assigned as co-correspondence author.It should be read:Jinlei Miao jinlei.miao@qdu.edu.cn The original article has been corrected.

Recent Progress of the Active Materials with Various Micro‑structures for Flexible Textile‑Based Supercapacitors

Flexible textile-based supercapacitors have exhibited great potential for use in e-textile systems due to their high flexibility,light weight and ease of integration into the textile materials.The capacitance and energy density of current textile-based supercapacitors,however,are insufficient to meet the high demands of wearable electronics and smart textiles.This review summarizes the recent progress of enhancement methods regarding textile-based supercapacitors,including the multidimen-sional nanostructure of active materials,the structural designs of textile substrates and the wearable softness.Furthermore,the remaining challenges and future prospects of constructing high-performance flexible textile-based supercapacitors for smart textiles and wearable electronics are also proposed.

Breathable Kirigami‑Shaped Ionotronic e‑Textile with Touch/Strain Sensing for Friendly Epidermal Electronics

Flexible ionotronic devices have great potential to revolutionize epidermal electronics.However,the lack of breathability in most ionotronic devices is a significance barrier to practical application.Herein,a breathable kirigami-shaped ionotronic e-textile with two functions of sensing(touch and strain)is designed,by integrating silk fabric and kirigami-shaped ionic hydrogel.The kirigami-shaped ionic hydrogel,combined with fluffy silk fabric,allows the ionotronic e-textile to achieve excellent breathability and comfortability.Furthermore,the fabricated ionotronic e-textile can precisely perform the function of touch sensing and strain perception.For touch-sensing,the ionotronic e-textile can detect the position of finger touching point with a fast response time(3 ms)based on the interruption of the ion field.For strain sensing,large workable strain range(>100%),inconspicuous drift(<0.78%)and long-term stability(>10,000 cycles)is demonstrated.On the proof of concept,a fabric keyboard and game controlling sleeve have been designed to display touch and strain sensing functions.The ionotronic e-textile break through the bottlenecks of traditional wearable ionotronic devices,suggesting a great promising application in future wearable epidermal electronics.