Bio-Inspired Artificial Perceptual Devices for Neuromorphic Computing and Gesture Recognition

Artificial perception technologies capable of sensing and feeling mechanical stimuli like human skins are critical enablers for electronic skins (E-Skins) needed to achieve artificial intelligence. However, most of the reported electronic skin systems lack the capability to process and interpret the sensor data. Herein, a new design of artificial perceptual system integrating ZnO-based synaptic devices with Pt/carbon nanofibers-based strain sensors for stimuli detection and information processing is presented. Benefiting from the controllable ion migration after indium doping, the device can emulate various essential functions, such as short-term/long-term plasticity, paired-pulse facilitation, excitatory post-synaptic current, and synaptic plasticity depending on the number, frequency, amplitude, and width of the applied pulses. The Pt/carbon nanofibers-based strain sensors can detect subtle human motion and convert mechanical stimuli into electrical signals, which are further processed by the ZnO devices. By attaching the integrated devices to finger joints, it is demonstrated that they can recognize handwriting and gestures with a high accuracy. This work offers new insights in designing artificial synapses and sensors to process and recognize information for neuromorphic computing and artificial intelligence applications.     

Recent Progress in Essential Functions of Soft Electronic Skin

Inspired by the human skin, electronic skins (e-skins) composed of various flexible sensors, such as strain sensor, pressure sensor, shear force sensor, temperature sensor, and humility sensor, and delicate circuits, are emerged to mimic the sensing functions of human skins. In this review, the strategies to realize the versatile functionalities of natural skin-like e-skins, including strain-, pressure-, shear force-, temperature- and humility-sensing abilities, as well as self-healing ability and other functions are summarized. Some representative examples of high-performance e-skins and their applications are outlined and discussed. Finally, the outlook of the future of e-skins is presented.     

Sebum-Membrane-Inspired Protein-Based Bioprotonic Hydrogel for Artificial Skin and Human-Machine Merging Interface

As an on-skin electronic device, artificial skin shows great potential in medical monitoring and personal electronics, which also holds promise to develop human-machine merging interfaces. However, merging artificial skins with human bodies is largely restricted by the dissimilarity of material compositions in existing artificial skins and biological tissues. Naturally conductive protein is a potential material candidate for artificial skins, nevertheless, it suffers from the critical issue of dehydration which harms its proton conductivity. Inspired by the sebum membrane of human skin, herein, a protein-based bioprotonic hydrogel (PBH) with reliable water retention ability is reported for artificial skins. The bovine serum albumin with natural proton conductivity is utilized in the PBH, and the glycerol that originally presents on human skin surface is used as an artificial sebum membrane to retain water. The PBH can act as a bioprotonic skin (B-skin) for collecting electrophysiological signals and self-powered sensing. Based on the B-skin, intelligent robot and cellphone control systems are demonstrated. Compared with present artificial skins, this B-skin is all made out of biological materials that are consistent with material components of human skin tissues including proteins, endogenous glycerol, and water. Such a B-skin may enable the development of next-generation human-machine merging interfaces.     

Piezoelectric Nanogenerators Derived Self-Powered Sensors for Multifunctional Applications and Artificial Intelligence

With the arrival of the Internet of Things (IoTs) era, there is a growing requirement for systems with many sensor nodes in a variety of fields of applications. The demands for wireless, sustainable and independent operation are becoming more and more important for large-scale sensor networks and systems. For these purposes, a self-powered sensory system that can utilize the self-harvested energy from its surroundings to drive the sensors and directly sense external stimuli has attracted great attention. The invention and rapid development of piezoelectric generators (PENGs), which take Maxwell's displacement current as the driving force, has been pushing forward research on self-powered active mechanical sensors, electronic skins, and human-robotic interaction. Here, this review starts with a brief introduction of piezoelectric materials, fabrication, and performance improvement. Then, the energy harvesters used for self-power systems based on recent progress are reviewed. After that, PENGs applications toward recent self-powered active sensors are divided into four aspects and highlighted, respectively. Moreover, some challenges and future directions for the self-powered multifunctional sensors are put forward. It is believed that through the continuous investigations into PENG-based self-powered active sensors, they will soon be used in touch screens, electronic skins, health care, environmental monitoring, and intelligence systems.     

Flexible Inorganic Piezoelectric Acoustic Nanosensors for Biomimetic Artificial Hair Cells

For patients who suffer from sensorineural hearing loss by damaged or loss of hair cells in the cochlea, biomimetic artificial cochleas to remedy the dis­advantages of existing implant systems have been intensively studied. Here, a new concept of an inorganic‐based piezoelectric acoustic nanosensor (iPANS) for the purpose of a biomimetic artificial hair cell to mimic the functions of the original human hair cells is introduced. A trapezoidal silicone‐based membrane (SM) mimics the function of the natural basilar membrane for frequency selectivity, and a flexible iPANS is fabricated on the SM utilizing a laser lift‐off technology to overcome the brittle characteristics of inorganic piezoelectric materials. The vibration amplitude vs piezoelectric sensing signals are theoretically examined based on the experimental conditions by finite element analysis. The SM is successful at separating the audible frequency range of incoming sound, vibrating distinctively according to varying locations of different sound frequencies, thus allowing iPANS to convert tiny vibration displacement of ≈15 nm into an electrical sensing output of ≈55 μV, which is close to the simulation results presented. This conceptual iPANS of flexible inorganic piezoelectric materials sheds light on the new fields of nature‐inspired biomimetic systems using inherently high piezoelectric charge constants.     

基于铁电材料的有机光电突触晶体管研究

模拟生物突触结构的设备是实现神经网络计算的可行方案之一,其中人工视网膜器件为机器视觉和图像识别的实现提供了有力支持。通过旋涂制备聚偏氟乙烯-三氟乙烯(P(VDF-TrFE))制备铁电栅层,热蒸发酞菁铜(CuPc)作为半导体层,探究该晶体管模拟突触功能的光电响应。实验结果表明,该光电晶体管在625 nm具有显著的光响应,其能够产生兴奋性突触后电流(EPSC)并实现短期可塑性到长期可塑性的转变以及高通滤波功能。利用剩余极化强度模拟了大脑学习过程中提前施加注意的行为。此外,以栅电压和光照作为独立输入逻辑信号,在单个晶体管中实现了“与”和“或”的布尔逻辑功能。上述结果表明,CuPc可以与铁电材料进行良好结合并制备出具有突触响应特点的光电晶体管,这为人工视网膜器件的开发提供了有机铁电器件的参考。     

矩形介质谐抵腔的格林函数问题

本文讨论了求解平面分层媒质系统的并矢格林函数问题的一种新方法。这一方法的特点就是把并矢格莱函数问题转化为标量格林函数来解决。文中详述了介质加载的矩形腔的并矢格林函数的求解方法和结果。     

基于全局无偏搜索策略的精英人工蜂群算法

针对精英人工蜂群算法（ABC_elite）加速收敛和早熟停滞现象的矛盾,提出一种改进算法（EABC_elite）.该算法通过在雇佣蜂阶段引入全局最优解加速收敛,同时通过普通个体平衡全局最优解过大的引导作用,因此全局最优解与普通个体的信息都能得到利用而算法仍能较好平衡.在观察蜂阶段引入普通个体避免算法早熟收敛.改进算法在加速收敛与防止早熟之间取得很好的平衡,总体上没有偏向任何方向,增强了ABC_elite的全局搜索能力.实验表明,改进算法的性能显著好于ABC_elite以及最近提出的几种较高水平的改进人工蜂群算法.     

基于遗传算法和人工神经网络的颅内压监测

通过对目前颅内压检测方法优缺点的分析,提出一种新型的颅内压检测方法——基于遗传算法和人工神经网络的颅内压监测。该方法利用误差反向传播神经网络建模,利用遗传算法优化,克服误差反向传播算法效率低下,易陷入局部极值的缺点。通过测量4～6个脑血流动力学参数,输入进此颅内压预测模型,即可得到所需颅内压值。     

Pressure Sensing and Electronic Amplification with Functionalized Graphite–Silicone Composite

A flexible yet electronically active composite that mimics mechanoreceptor neurons in the human skin is synthesized, generating voltage oscillations whose frequency increases with pressure. By encoding pressure into frequency, the sensor achieves a high pressure sensitivity (<10 Pa). The ability to sense pressure and to amplify signals arises from the robust negative differential resistance of functionalized graphitic flakes in silicone.     

Thermally Stable,Biocompatible, and Flexible Organic Field‐Effect Transistors and Their Application in Temperature Sensing Arrays for Artificial Skin

Application of degradable organic electronics based on biomaterials, such as polylactic‐co‐glycolic acid and polylactide (PLA), is severely limited by their low thermal stability. Here, a highly thermally stable organic transistor is demonstrated by applying a three‐arm stereocomplex PLA (tascPLA) as dielectric and substrate materials. The resulting flexible transistors are stable up to 200 °C, while devices based on traditional PLA are damaged at 100 °C. Furthermore, charge‐ trapping effect induced by polar groups of the dielectric is also utilized to significantly enhance the temperature sensitivity of the electronic devices. Skin‐like temperature sensor array is successfully demonstrated based on such transistors, which also exhibited good biocompatibility in cytotoxicity measurement. By presenting combined advantages of transparency, flexibility, thermal stability, temperature sensitivity, degradability, and biocompatibility, these organic transistors thus possess a broad applicability such as environment friendly electronics, implantable medical devices, and artificial skin.     

一种快速高效的人工蜂群算法

针对人工蜂群算法收敛速度慢和易陷入局部最优的缺点,在雇佣蜂搜索阶段提出了一种基于多维搜索和一维搜索的混合搜索策略,能克服单一一维搜索下收敛速度慢的缺点,有效加快收敛速度;提出了新的跟随蜂蜜源选择策略,可保证种群多样性,增强算法全局搜索能力。通过对12个基准测试函数进行仿真实验并与原算法进行比较,其结果表明改进的算法在收敛速度和精度上均优于人工蜂群算法。     

基于慢门限与快门限的雷达回波恒虚警处理算法研究

本文研究了慢门限恒虚警处理和快门限恒虚警处理算法,针对慢门限恒虚警电路模型使用对数减法来代替除法运算以提高效率;针对快门限恒虚警处理电路模型存在的边缘效应问题,采用双侧单元平均选大的解决方案,使雷达检测系统始终处于恒虚警状态。     

人工免疫系统的研究进展与展望

人工免疫是受生物免疫系统的启发而发展起来的,并逐步成为人工智能研究的热点。首先介绍人工免疫系统的生物原型,并对免疫系统群体计算中的免疫学习、免疫记忆、免疫遗传等算法进行描述;对近几年典型的人工免疫算法与系统进行了深入探讨,通过人工免疫算法在不同领域的应用,展示人工免疫系统在解决复杂问题时具有自组织、自适应、鲁棒性的特点。最后提出免疫算法在未来一段时间内的发展趋势与应用领域,尤其是在免疫协同防御、人工免疫系统与模糊系统集成、量子技术与免疫算法的融合以及人工免疫在无人驾驶技术中的应用,是未来人工免疫系统的发展趋势和研究方向。     

北斗/INS组合导航中人工鱼群粒子滤波的应用

为解决粒子滤波中的粒子退化和枯竭问题,提出一种动态人工鱼群粒子滤波算法,该算法在粒子滤波重采样过程中引入人工鱼群算法的觅食和聚群行为,并依据概率密度的动态比值动态调整人工鱼的移动步长,此算法提升了粒子的多样性,克服了粒子退化及枯竭问题;推动粒子向优选区域逼近,并提高了粒子的全局搜索能力,避免粒子陷入局部最优。将改进的动态人工鱼群粒子滤波在北斗/INS紧组合的模型上进行应用,并通过仿真与人工鱼群粒子滤波及标准粒子滤波算法PF相比较。仿真结果表明,动态人工鱼群粒子滤波可显著提高估算精度,从而为在利用北斗和INS在紧组合导航时提供了新的方法。     

Bessel函数与三角函数之积的级数展开及在微波滤波器中的应用

根据对平面波函数运用Fourier-Bessel定理,经过一系列推导并进行反Fourier变换,得到了直角坐标系下Bessel函数与三角函数之积的一种级数展开,该表达式应用到矩-圆波导结的计算中,能解析地推出其广义S参数,得到与文献和HFSS软件较为一致的结果.计算了Ku和Ka频段多种尺寸的有厚度的矩形孔的耦合系数,并与文献、实验数据进行了比较,吻合较好,设计了一个Ku频段6阶类椭圆函数滤波器,实验性能与理论结果一致.     

假目标干扰机与反辐射武器的电磁兼容分析

针对综合雷达攻击中假目标干扰机与反辐射武器的电磁兼容问题，分析了反辐射导引头受扰原理，建立了首次跟踪概率的数学模型。并通过仿真研究了影响首次跟踪概率的各因素，提出并确定了非压制区，将其作为判定电磁兼容性的依据。     

人工免疫系统进展与展望

本文评述人工免疫系统的历史、研究现状和进一步发展的方向.着重论述人工免疫系统的机理、算法和应用,总结了免疫算法的一般步骤,比较了其与神经网络、进化计算以及一般确定性优化算法的异同.在总结人工免疫系统存在问题的基础上,探讨了进一步研究的方向.     

卫星IP数据资源的接收及使用

从卫星IP数据资源的系统组成、系统的安装及数据的接收等方面进行综述,给出卫星IP数据接收的方法,帮助读者全面了解卫星远程教育资源接收与利用的新知识、新技术,进而推动我国现代远程教育朝着健康、快速、效益显著的方向发展。