Flexible electronics have attracted extensive attention across a wide range of fields due to their potential for preventive medicine and early disease detection.Microfiber-based textiles,encountered in everyday life,have emerged as promising platforms with integrated sensing capabilities.Microfluidic technology has been recognized as a promising avenue for the development of flexible conductive microfibers and has made significant achievements.In this review,we provide a comprehensive overview of the state-of-the-art advancements in microfiber-based flexible electronics fabricated using microfluidic platforms.Firstly,the fundamental strategies of the microfluidic fabrication of conductive microfibers with different structures and morphologies are introduced.Subsequently,attention is then directed towards the diverse applications of these microfibers in bioelectronics.Finally,we offer a forwardlooking perspective on the future challenges about microfluidic-derived microfibers in flexible bioelectronics.
Microfibers from natural products are endowed with remarkable biocompatibility,biodegradability,sustainable utilization as well as environmental protection char-acteristics etc.Benefitting from these advantages,microfibers have demonstrated their prominent values in biomedical applications.This review comprehensively summarizes the relevant research progress of sustainable microfibers from natural products and their biomedical applications.To begin,common natural elements are introduced for the microfiber fabrication.After that,the focus is on the specific fabri-cation technology and process.Subsequently,biomedical applications of sustainable microfibers are discussed in detail.Last but not least,the main challenges during the development process are summarized,followed by a vision for future development opportunities.
Soft strain sensors that can transduce stretch stimuli into electrical readouts are promising as sustainable wearable electronics.However,most strain sensors cannot achieve highly-sensitive and wide-range detection of ultralow and high strains.Inspired by bamboo structures,anti-freezing microfibers made of conductive poly(vinyl alcohol)hydrogel with poly(3,4-ethylenedioxythiphene)-poly(styrenesulfonate)are developed via continuous microfluidic spinning.The microfibers provide unique bamboo-like structures with enhanced local stress to improve both their length change and resistance change upon stretching for efficient signal conversion.The microfibers allow highlysensitive(detection limit:0.05%strain)and wide-range(0%-400%strain)detection of ultralow and high strains,as well as features of good stretchability(485%strain)and anti-freezing property(freezing temperature:-41.1°C),fast response(200 ms),and good repeatability.The experimental results,together with theoretical foundation analysis and finite element analysis,prove their enhanced length and resistance changes upon stretching for efficient signal conversion.By integrating microfluidic spinning with 3D-printing technique,the textiles of the microfibers can be flexibly constructed.The microfibers and their 3D-printed textiles enable highperformance monitoring of human motions including finger bending and throat vibrating during phonation.This work provides an efficient and general strategy for developing advanced conductive hydrogel microfibers as highperformance wearable strain sensors.
In various biomedical fields,noninvasive medical procedures are favored over invasive techniques,as the latter require major incisions or surgeries that cause bleeding,pain,and tissue scarring.The increased use of noninvasive biomedical equipment has created a demand for effective energy storage devices that are sufficiently compact to be used as a power source,easy to commercialize,and bio-friendly.Herein,we report the facile synthesis of nickel molybdenum oxide nanoparticle-infused biocarbon microfibers(NiMoO NPs@BCMFs)as a novel energy storage material.The microfibers were derived from the bracket fungus Laetiporus sulphureus.In a three-electrode system,the NiMoO NPs@BCMFs/nickel foam(NF)electrode delivered an areal capacity of 113µAh cm^(-2)at 1.5 mA cm^(-2),with excellent cycling stability.Its capacity retention was 104%,even after 20,000 cycles.Bare BCMFs were also synthesized from the fungal biomass to fabricate a negative BCMFs/NF electrode.This,together with the positive NiMoO NPs@BCMFs/NF electrode,was used to construct a bio-friendly(hybrid-type)micro-supercapacitor(BMSC),which exhibited maximum energy and power density values of 56µWh cm^(-2)and 11,250µW cm^(-2),respectively.When tested for its ability to power biomedical electronics,the BMSC device successfully operated an electrical muscle stimulator,inducing potential signals into a volunteer in real-time application.
Optical micro/nanofibers(MNFs)taper-drawn from silica fibers possess intriguing optical and mechanical properties.Recently,MNF array or MNFs with identical geometries have been attracting more and more attention,however,current fabrication technique can draw only one MNF at a time,with a low drawing speed(typically 0.1 mm/s)and a complicated process for high-precision control,making it inefficient in fabricating multiple MNFs.Here,we propose a parallel-fabrication approach to simultaneously drawing multiple(up to 20)MNFs with almost identical geometries.For fiber diameter larger than 500 nm,measured optical transmittances of all as-drawn MNFs exceed 96.7%at 1550-nm wavelength,with a diameter deviation within 5%.Our results pave a way towards high-yield fabrication of MNFs that may find applications from MNF-based optical sensors,optical manipulation to fiber-to-chip interconnection.
Facile and efficient photocatalysts using sunlight,as well as fast and sensitive surface-enhanced Raman spectroscopy(SERS)substrates,are urgently needed for practical degradation of tetracycline(TC).To meet these requirements,a new paradigm for PI/TiO_(2)/Ag organic‒inorganic ternary flexible microfibers based on semiconducting titanium dioxide(TiO_(2)),the noble metal silver(Ag)and the conjugated polymer polyimide(PI)was developed by engineering a simple method.Under sunlight,the photocatalytic characteristics of the PI/TiO_(2)/Ag flexible microfibers containing varying amounts of Ag quantum dots(QDs)were evaluated with photocatalytic degradation of TC in aqueous solution.The results demonstrated that the amount of Ag affected the photocatalytic activity.Among the tested samples,PI/TiO_(2)/Ag-0.07(93.1%)exhibited a higher photocatalytic degradation rate than PI/TiO_(2)(25.7%),PI/TiO_(2)/Ag-0.05(77.7%),and PI/TiO_(2)/Ag-0.09(63.3%).This observation and evaluation conducted in the present work strongly indicated a charge transfer mechanism.Moreover,the PI/TiO_(2)/Ag-0.07 flexible microfibers exhibited highly sensitive SERS detection,as demonstrated by the observation of the Raman peaks for TC even at an extremely low concentration of 10–10 moles per liter.The excellent photocatalytic performance and SERS detection capability of the PI/TiO_(2)/Ag flexible microfibers arose from the Schottky barrier formed between Ag and TiO_(2)and also from the outstanding plasmonic resonance and visible light absorptivity of Ag,along with immobilization by the PI.The successful synthesis of PI/TiO_(2)/Ag flexible microfibers holds significant promise for sensitive detection and efficient photocatalytic degradation of antibiotics.
目的探索CX3CR1对创伤性骨髓炎大鼠骨骼肌微纤维、ERK/MAPK信号通路及炎症反应的影响。方法选取30只SPF级SD雄性大鼠,依据随机数字表法分为健康组、模型组、CX3CR1抑制组,每组10只。除健康组外,其余各组均建立创伤性骨髓炎模型。其中健康组、模型组大鼠均每日常规腹腔注射生理盐水,CX3CR1干预组向残腔内注射CX3CR1中和抗体进行处理。采用ELISA法检测血清中IL-6、IL-10、IL-1β、TGF-β水平,应用改良X线Norden评分检测骨骼肌微纤维,HE染色观察病理变化,免疫印迹及PCR检测股骨组织中细胞外信号调节蛋白激酶(Extracellular regulated protein kinase,ERK1/2)、丝裂原活化蛋白激酶(Mitogen activated protein kinase,MAPK)蛋白及mRNA表达。结果与健康组比较,模型组TGF-β、IL-1β、IL-10、IL-6等炎症因子含量均升高(P<0.05);与模型组比较,CX3CR1抑制组炎症因子含量降低(P<0.05)。与健康组比较,模型组随时间推移X线Norden评分升高(P<0.05);与模型组比较,CX3CR1抑制组X线Norden评分降低(P<0.05)。HE染色显示,健康组骨质完好;模型组可见大量炎性细胞浸润、灶性脓肿及坏死灶;CX3CR1抑制组大鼠的骨质明显改善,炎症反应降低。与健康组比较,模型组ERK1/2、MAPK蛋白及mRNA表达升高(P<0.05);与模型组比较,CX3CR1抑制组ERK1/2、MAPK蛋白及mRNA表达降低(P<0.05)。结论抑制CX3CR1可改善创伤性骨髓炎大鼠的疾病反应,可能与降低炎症反应、ERK/MAPK信号通路以及改善骨骼肌微纤维相关。