【作者】 张敏；

【导师】 刘志海；

【作者基本信息】 哈尔滨工程大学 ， 光学工程， 2023， 博士

【摘要】 目前,生物医学研究对光纤传感器提出了新的要求,不仅需要高度灵敏、高度集成,还要兼具柔性和生物相容性,即光纤传感器需适配生物界面并且不会引起生物体的排异反应。蜘蛛丝不仅具有生物相容性与柔性,还兼具导光能力、湿敏特性及良好的力学特性,并能与现有光器件集成以实现光学传感。因此,蜘蛛丝具有研究价值。然而,目前蜘蛛丝光波导用于传感时所采用的光耦合方式不仅集成度低、易受振动干扰,还会令器件受蜘蛛丝超收缩湿度阈值的限制而无法在高湿度环境工作。光刻技术虽能用于制作高度集成的蜘蛛丝光波导器件,但其工序繁琐、价格高昂,并且这类蜘蛛丝集成光学器件至今未被用于传感。因此,蜘蛛丝在光学传感领域的研究目前仍处于起步阶段。为推进集成式蜘蛛丝光学传感器件的研发与应用,仍需解决以下问题:如何使蜘蛛丝光学传感器件具备较广的湿度工作范围;如何实现蜘蛛丝与其他光学器件的低成本、稳定集成。本文以基于蜘蛛丝的干涉型光纤传感器为研究对象,构建了低成本、高稳定的蜘蛛丝干涉型光学传感器件,提高了蜘蛛丝光学器件的集成度,并具体完成了以下工作:首先,基于对高灵敏法布里-珀罗干涉型光纤传感器的理论分析,蜘蛛牵引丝的超收缩特性被用于制作高灵敏的法布里-珀罗湿度传感器,其平均灵敏度达11.89 nm/%RH。该传感器还可用于呼吸监测,能够实时动态监测高频及低频呼吸,监测距离可达30 cm远。该传感器将蜘蛛丝用作驱动元件实现了高灵敏度,但并未使蜘蛛丝参与光学干涉过程。传感器的整体尺寸较大,宽度达26 mm,器件集成度较低。其次,基于蜘蛛包卵丝吸水膨胀的特性,提出了蜘蛛丝-光纤集成式法布里-珀罗湿度传感器的制作方法,蜘蛛丝参与了光的反射过程。该传感器的灵敏度仅-0.29 nm/%RH,但器件的整体直径降低至100μm,集成度显著提高。这种集成式蜘蛛丝光学传感器件具备结构小巧、便于携带、温度串扰较低的特点。随后,基于蜘蛛牵引丝吸水后结晶区由取向一致转变为无序状态的结构特性,将蜘蛛丝用作了折射率随湿度变化的光波导,通过缠绕法构建了蜘蛛丝-光纤集成式模式干涉型传感器。这种新型集成方式使蜘蛛丝传感器件免受牵引丝超收缩湿度阈值对工作范围的限制,湿度传感范围为30%RH～89%RH。传感器的整体直径降至约13μm,器件集成度进一步提升。该器件的成本低且集成度较高,平均灵敏度提升至0.53 nm/%RH,为制作蜘蛛丝-光纤集成式光学器件提供了新的手段。最后,基于蜘蛛牵引丝的多模光波导特性,利用倏逝场光耦合的方式实现了低成本的、稳定的蜘蛛丝光耦合结构。蜘蛛丝被用作兼具光信号传输与传感功能的微米级光波导,构建了蜘蛛丝光学模式干涉仪,并提出分步封装法将干涉仪封装在柔性热敏材料中,隔绝了外界湿度变化对蜘蛛丝的影响。蜘蛛丝模式干涉仪的总直径不到8μm,器件高度集成,并对温度变化近乎线性响应,灵敏度为-1.15 nm/℃。蜘蛛丝模式干涉仪具有结构紧凑、光耦合稳定、便携、免疫外界湿度影响等优势,为构建以蜘蛛丝为核心的集成式光学器件提供了新的方法与途径。总体而言,本文提出了多种将蜘蛛丝与光纤进行集成的方法,利用蜘蛛丝研制了多种干涉型光学传感器件,并且这些器件的湿度工作范围均不受超收缩湿度阈值的限制。这些研究为蜘蛛丝在光学传感领域的进一步应用提供了行之有效的方法。更多还原

【Abstract】 Currently,biomedical research has put forward new requirements for optical fiber sensors(OFS),OFS should not only have high sensitivity and integration,but also have flexibility and biocompatibility,which means OFS should match biological interface without causing immune rejection of organisms.Spider silk(SS)has biocompatibility,flexibility,light-guiding ability,humidity-sensitive property,and good mechanical property,and can be integrated with optic devices to realize optical sensing.Therefore,SS has research value.However,the optical coupling method for the SS biophotonic waveguide used in sensing has low integration and poor vibration resistance,and the SS-based optic device cannot work in the high humidity range because of the humidity threshold limitation caused by SS supercontraction.Photolithography technology can be used to make highly integrated SS-based optic devices,but its fabrication process is complex and expensive,and the SS-based optic device made by using photolithography technology has not yet been used for optical sensing.Overall,the research on SS in the field of optical sensing is still in its infancy.To promote the development and application of integrated SS-based optical sensing devices,the following issues need to be addressed: how to make the SS-based device has a wide humidity working range;how to achieve cheap and stable integration of spider silk and other optical devices.This thesis takes SS-based interferometric OFS as the research object,develops cheap and stable SS-based interferometric sensing devices,and improves the integration of the SS-based optic device.The completed works are listed as follows:First,based on the theoretical analysis of constructing the highly sensitive Fabry-Perot(FP)interferometric OFS,the supercontraction of spider dragline silk(SDS)is used in the fabrication of the highly-sensitive F-P interferometric humidity sensor,whose average sensitivity is 11.89 nm/%RH.The sensor is capable of respiratory monitoring,and it can detect fast and slow respiration in real time with a monitoring distance up to 30 cm.The sensor has high sensitivity by using the SS as a driving component,and the SS is not involved in the optical interference process.The whole structure of the sensor is a bit big,its width reaches 26 mm,so that the integration of the sensor is low.Next,based on the water absorption and swelling property of spider egg-sac silk,an SSfiber integrated F-P humidity sensor fabrication method is proposed,and the SS participates in the reflection process of light beam.The sensor’s sensitivity is only-0.29 nm/%RH,but the whole diameter of sensor is reduced to 100 μm,the integration is greatly improved.This integrated SS-based OFS has compact structure,portability,and low-temperature cross-talking.Then,based on the structure-property of SDS,that is,the consistent orientation of the crystals in SDS will move to the disordered state after the water absorption,SS is used as a humidity-sensitive optical waveguide in the construction of an integrated multimode interference optical sensor based the winding method.This new kind of integration method makes the SS-based sensor avoid the limitation of supercontraction humidity threshold,and the humidity sensing range is 30%RH～89%RH.The whole diameter of the sensor is reduced to about 13 μm,and the sensor’s integration is further improved.The proposed sensor has low cost and high integration,and the average sensitivity is improved to 0.53 nm/%RH,which provides a new method for the fabrication of the SS-fiber integrated optic devices.Finally,based on the multimode optical waveguide property of SDS,the evanescent field optical coupling method is used to realize the cheap and stable SS light coupling structure.Spider silk is used as a micron optical waveguide which has light transmission and sensing functions to construct the SS-based optical mode interferometer.A two-step packaging method is proposed and used to embed the interferometer in the flexible thermosensitive material to avoid the influence of humidity variety on SS.The diameter of the SS-based mode interferometer’s core structure is less than 8 μm,the interferometer has high integration and linear response to temperature,and the sensitivity is-1.15 nm/℃.The SS-based interferometer has compact structure,stable optical coupling,portability,and resistance to humidity variety,which provides a new way to fabricate integrated SS-based optic devices.Overall,this thesis proposes kinds of methods for integrating SS with optical fibers,and develops interferometric optical sensing devices by using SS.The proposed SS-based devices are not limited by the humidity threshold of SS supercontraction.These studies provide effective methods for the further application of SS in the field of optical sensing.更多还原