生物医学中的植入式电子系统的现状与发展

"植入式电子学"已成为生物医学电子学中一个极为重要的组成部分.在对目前生物医学中各种典型植入式电子系统的分析后,本文总结出了植入式电子系统的综合性结构模型,并结合国际上有关植入式电子系统最新研究的进展,讨论了系统实现的关键技术、难点以及可能的解决方法,最后讨论了植入式电子系统的发展方向.     

More Than Energy Harvesting in Electret Electronics-Moving toward Next-Generation Functional System

Electrets are normally applied for energy conversion from mechanical vibration sources in the environment to electrical power without any friction, which induces electric device sustainability and mechanically robust. It functions for electron storage and electrostatic/triboelectric effect, whose electrical/mechanical performance dramatically benefits energy harvesters, self-powered sensors, and even intelligent/sustainable systems. To summarize the progress of electret-based electronics, this review proposes three key issues around enhanced energy harvesting toward sensors and sustainable systems. First, with the properties of long-term charge storage characteristics and the contactless mechanism for energy harvesting, the enhancement effect in electret from MEMS devices, porous microstructure devices, and multilayer electret devices are carefully assessed with the output power from various devices. Second, the multi-functional applications aspect along with the triboelectric coupling effect and artificial piezoelectric materials are discussed as future electret devices, for example, polydimethylsiloxane materials. Third, more than energy harvesting, machine learning-enabled methodology in electret electronics can be more reliable and sustainable, dramatically contributing to the living standard of the society. Electret technologies on the future development trends are finally analyzed and strengthened toward multifunctional, sustainable, and intelligent systems along with the upcoming technologies in coupling mechanism, artificial composite materials, and machine learning in data fusion.     

Wearable and Implantable Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs) are a promising technology to convert mechanical energy to electrical energy based on coupled triboelectrification and electrostatic induction. With the rapid development of functional materials and manufacturing techniques, wearable and implantable TENGs have evolved into playing important roles in clinic and daily life from in vitro to in vivo. These flexible and light membrane‐like devices have the potential to be a new power supply or sensor element, to meet the special requirements for portable electronics, promoting innovation in electronic devices. In this review, the recent advances in wearable and implantable TENGs as sustainable power sources or self‐powered sensors are reviewed. In addition, the remaining challenges and future possible improvements of wearable and implantable TENG‐based self‐powered systems are discussed.     

Emerging Design Strategies Toward Developing Next-Generation Implantable Batteries and Supercapacitors

In recent years, the development of implantable bioelectronics has garnered significant attention. With the continuous advancement of IoT and information technology, implantable bioelectronics can be utilized more effectively for health monitoring to enhance treatment outcomes, reduce healthcare costs, and improve quality of life. Implantable energy storage devices have been widely studied as critical components for energy supply. Conventional power sources are bulky, inflexible, and potentially contain materials that are dangerous to the body. Meanwhile, human tissues are soft, flexible, dynamic, and closed, which puts new requirements on energy storage devices to improve the safety, stability, and matching of implantable batteries or supercapacitors. Herein, recent advances in state-of-the-art nonconventional power options for implantable electronics, specifically biocompatible, miniaturized, stretchable/deformable, biodegradable/bioresorbable, edible, and injectable energy storage devices, are reviewed in this paper. The material strategy and architectural design of the next-generation implantable energy storage device are discussed, including the selection principle of electrolytes, the all-in-one structure design strategy, and the way to realize self-charging. Finally, the challenges and prospects of emerging design strategies toward developing next-generation implantable batteries and supercapacitors for the future are put forward.     

Anhydride‐Assisted Spontaneous Room Temperature Sintering of Printed Bioresorbable Electronics

Bioresorbable electronic devices are promising replacements for conventional build‐to‐last electronics in implantable biomedical systems and consumer electronics. However, bioresorbable devices are typically achieved by complex complementary metal oxide semiconductor fabrication processes that minimize exposure to humidity. Emerging printable techniques for bioresorbable electronics demand further improvement in electrical conductivity and mechanical robustness. This paper presents a room‐temperature spontaneous sintering method of bioresorbable inks that contain zinc nanoparticles and anhydride. The entire process can be conducted in atmosphere environment under 90% humidity within 300 min. It has minimum requirement for external heating and special ambient conditions, allowing humidity to trigger the surface chemistry of zinc nanoparticles and spontaneous welding between neighboring nanoparticles. The resulting bioresorbable patterns are highly conductive (σ = 72 400 S m^?1) and mechanically robust (>1500 bending cycles) to enable practical applications. A radio circuit achieved through the above method can operate stably over 14 days in air and disappear in water for less than 30 min. The spontaneous room‐temperature sintering represents a rapid and energy‐efficient approach to achieve high‐performance bioresorbable electronics with improved mechanical robustness and electrical performance, leading to broader impacts in the areas of healthcare, information security, and consumer electronics.     

A Highly Stretchable Fiber‐Based Triboelectric Nanogenerator for Self‐Powered Wearable Electronics

The development of flexible and stretchable electronics has attracted intensive attention for their promising applications in next‐generation wearable functional devices. However, these stretchable devices that are made in a conventional planar format have largely hindered their development, especially in highly stretchable conditions. Herein, a novel type of highly stretchable, fiber‐based triboelectric nanogenerator (fiber‐like TENG) for power generation is developed. Owing to the advanced structural designs, including the fiber‐convolving fiber and the stretchable electrodes on elastic silicone rubber fiber, the fiber‐like TENG can be operated at stretching mode with high strains up to 70% and is demonstrated for a broad range of applications such as powering a commercial capacitor, LCD screen, digital watch/calculator, and self‐powered acceleration sensor. This work verifies the promising potential of a novel fiber‐based structure for both power generation and self‐powered sensing.     

Edible Electronics: Biocompatible and Biodegradable Materials for Organic Field‐Effect Transistors (Adv. Funct. Mater. 23/2010)

Biocompatible‐ingestible electronic circuits and capsules for medical diagnosis and monitoring are currently based on traditional silicon technology. Organic electronics has huge potential for developing biodegradable, biocompatible, bioresorbable, or even metabolizable products. An ideal pathway for such electronic devices involves fabrication with materials from nature, or materials found in common commodity products. Transistors with an operational voltage as low as 4–5 V, a source drain current of up to 0.5 μA and an on‐off ratio of 3–5 orders of magnitude have been fabricated with such materials. This work comprises steps towards environmentally safe devices in low‐cost, large volume, disposable or throwaway electronic applications, such as in food packaging, plastic bags, and disposable dishware. In addition, there is significant potential to use such electronic items in biomedical implants.     

Biocompatible and Biodegradable Materials for Organic Field‐Effect Transistors

Biocompatible‐ingestible electronic circuits and capsules for medical diagnosis and monitoring are currently based on traditional silicon technology. Organic electronics has huge potential for developing biodegradable, biocompatible, bioresorbable, or even metabolizable products. An ideal pathway for such electronic devices involves fabrication with materials from nature, or materials found in common commodity products. Transistors with an operational voltage as low as 4–5 V, a source drain current of up to 0.5 μA and an on‐off ratio of 3–5 orders of magnitude have been fabricated with such materials. This work comprises steps towards environmentally safe devices in low‐cost, large volume, disposable or throwaway electronic applications, such as in food packaging, plastic bags, and disposable dishware. In addition, there is significant potential to use such electronic items in biomedical implants.     

Ultrasound‐Induced Wireless Energy Harvesting for Potential Retinal Electrical Stimulation Application

Retinal electrical stimulation for people with neurodegenerative diseases has shown to be feasible for direct excitation of neurons as a means of restoring vision. In this work, a new electrical stimulation strategy is proposed using ultrasound‐driven wireless energy harvesting technology to convert acoustic energy to electricity through the piezoelectric effect. The design, fabrication, and performance of a millimeter‐scale flexible ultrasound patch that utilizes an environment‐friendly lead‐free piezocomposite are described. A modified dice‐and‐fill technique is used to manufacture the microstructure of the piezocomposite and to generate improved electrical and acoustic properties. The as‐developed device can be attached on a complex surface and be driven by ultrasound to produce adjustable electrical outputs, reaching a maximum output power of 45 mW cm^?2. Potential applications for charging energy storage devices and powering commercial electronics using the device are demonstrated. The considerable current signals (e.g., current >72 µA and current density >9.2 nA µm^?2) that are higher than the average thresholds of retinal stimulation are also obtained in the ex vivo experiment of an implanted environment, showing great potential to be integrated on implanted biomedical devices for electrical stimulation application.     

Hybrid Smart Fiber with Spontaneous Self‐Charging Mechanism for Sustainable Wearable Electronics

Smart wearable electronics that are fabricated on light‐weight fabrics or flexible substrates are considered to be of next‐generation and portable electronic device systems. Ideal wearable and portable applications not only require the device to be integrated into various fiber form factors, but also desire self‐powered system in such a way that the devices can be continuously supplied with power as well as simultaneously save the acquired energy for their portability and sustainability. Nevertheless, most of all self‐powered wearable electronics requiring both the generation of the electricity and storing of the harvested energy, which have been developed so far, have employed externally connected individual energy generation and storage fiber devices using external circuits. In this work, for the first time, a hybrid smart fiber that exhibits a spontaneous energy generation and storage process within a single fiber device that does not need any external electric circuit/connection is introduced. This is achieved through the employment of asymmetry coaxial structure in an electrolyte system of the supercapacitor that creates potential difference upon the creation of the triboelectric charges. This development in the self‐charging technology provides great opportunities to establish a new device platform in fiber/textile‐based electronics.     

Steady as she blows [wind power, energy storage]

Power electronics and exotic energy storage devices are making wind power steady enough to compete with conventional electricity sources. Systems based on advanced power electronics and energy storage devices are massaging and managing power flows from wind turbines, enabling them to contribute to electricity grids without putting those grids at risk. Not only are the technologies making wind power more palatable to grid operators, they are even making it possible for engineers to finally harness wind energy's tremendous potential in wind-swept, remote locales. This article discusses the power electronic and energy storage technologies used in wind power.     

Printed Solar Cells and Energy Storage Devices on Paper Substrates

Paper is a flexible material, commonly used for information storage, writing, packaging, or specialized purposes. It also has strong appeal as a substrate in the field of flexible printed electronics. Many applications, including safety, merchandising, smart labels/packing, and chemical/biomedical sensors, require an energy source to power operation. Here, progress regarding development of photovoltaic and energy storage devices on cellulosic substrates, where one or more of the main material layers are deposited via solution processing or printing, is reviewed. Paper can be used simply as the flexible substrate or, exploiting its porous fiber‐like nature, as an active film by infiltration or copreparation with electronic materials. Solar cells with efficiencies of up to 9% on opaque substrates and 13% on transparent substrates are demonstrated. Recent developments in paper‐based supercapacitors and batteries are also reviewed with maximum achieved capacity of 1350 mF cm^?2 and 2000 mAh g^?1, respectively. Analyzing the literature, it becomes apparent that more work needs to be carried out in continuing to improve peak performance, but especially stability and the application of printing techniques, even roll‐to‐roll processing, over large areas. Paper is not only environmentally friendly and recyclable, but also thin, flexible, lightweight, biocompatible, and inexpensive.     

In Vivo Self‐Powered Wireless Transmission Using Biocompatible Flexible Energy Harvesters

Additional surgeries for implantable biomedical devices are inevitable to replace discharged batteries, but repeated surgeries can be a risk to patients, causing bleeding, inflammation, and infection. Therefore, developing self‐powered implantable devices is essential to reduce the patient's physical/psychological pain and financial burden. Although wireless communication plays a critical role in implantable biomedical devices that contain the function of data transmitting, it has never been integrated with in vivo piezoelectric self‐powered system due to its high‐level power consumption (microwatt‐scale). Here, wireless communication, which is essential for a ubiquitous healthcare system, is successfully driven with in vivo energy harvesting enabled by high‐performance single‐crystalline (1 ? x )Pb(Mg_1/3Nb_2/3)O₃?(x )Pb(Zr,Ti)O₃ (PMN‐PZT). The PMN‐PZT energy harvester generates an open‐circuit voltage of 17.8 V and a short‐circuit current of 1.74 µA from porcine heartbeats, which are greater by a factor of 4.45 and 17.5 than those of previously reported in vivo piezoelectric energy harvesting. The energy harvester exhibits excellent biocompatibility, which implies the possibility for applying the device to biomedical applications.     

Flexible energy storage devices for wearable bioelectronics

With the growing market of wearable devices for smart sensing and personalized healthcare applications,energy stor-age devices that ensure stable power supply and can be constructed in flexible platforms have attracted tremendous research in-terests.A variety of active materials and fabrication strategies of flexible energy storage devices have been intensively studied in recent years,especially for integrated self-powered systems and biosensing.A series of materials and applications for flex-ible energy storage devices have been studied in recent years.In this review,the commonly adopted fabrication methods of flex-ible energy storage devices are introduced.Besides,recent advances in integrating these energy devices into flexible self-powered systems are presented.Furthermore,the applications of flexible energy storage devices for biosensing are summar-ized.Finally,the prospects and challenges of the self-powered sensing system for wearable electronics are discussed.     

GaN技术发展新趋势

氮化镓(GaN)是第三代半导体的典型代表,受到学术界和产业界的广泛关注,正在成为未来超越摩尔定律所依靠的重要技术之一。对于射频(RF)GaN技术,在电信和国防两大主要应用增长行业,尤其是军用领域对先进雷达和通信系统不断增加的需求,推动了RF GaN器件向更高频率、更大功率和更高可靠性发展。文章梳理了在该领域中GaN RF/微波HEMT、毫米波晶体管和单片微波集成电路(MMIC)、GaN器件空间应用可靠性和抗辐射加固等技术发展的脉络。在功率电子方面,对高效、绿色和智能化能源的需求拉动GaN功率电子、电源变换器向快速充电、高效和小型化方向发展。简述了应用于纯电动与混合动力电动汽车(EV/HEV)、工业制造、电信基础设施等场合的GaN功率器件的研发进展和商用情况。在数字计算特别是量子计算前沿,GaN是具有应用前景的技术之一。介绍了GaN计算和低温电子技术研究的几个亮点。总而言之,对GaN技术发展几大领域发展的最新趋势作了概括性描述,勾画出技术发展的粗略线条。     

微电子技术在生物医学中的应用与发展

微电子技术与生物医学之间有着非常紧密的联系。一方面微电子技术的发展，特大大地推动生物医学的发展，另一方面生物医学的研究成果同样也将对微电子技术的发展起着巨大的促进作用。本文将从生物医学电子学的几个重要发展领域：生物医学传感器、神经电极、植入式电子系统、监护技术、生物芯片、分子和生物分子电子学以及仿生系统等的基本概念出发，结合国际上最新进展介绍微电子技术和生物医学的相互作用与发展，并总结国际上的最新技术和研究动向。     

风电机组低压穿越中的电力电子技术（上）

为了降低大规模风电并网对电力系统的影响．世界各国的电网运营商相继制定新的并网准则对并网风电场的输出特性作出严格规定,并网导则中的一项重要内容是要求风电场具有低压穿越（LVRT）能力。电力电子技术是提高风电场低电压穿越能力的重要手段,对于变速风电机组,电力电子设备已成为其标准配置,在低电压穿越过程中起到至关重要的作用;对...     

电力电子行业在新能源建设中迎来新的发展机遇

本文介绍了电力电子技术在新时期中对科技进步和经济建设中将发挥越来越重要的作用。常见新能源领域和涉及到的常用工程。还重点介绍了电力电子技术在新能源领域的应用,进而阐述了电力电子技术发展的前景。     

风电机组低压穿越中的电力电子技术(下)

为了降低大规模风电并网对电力系统的影响,世界各国的电网运营商相继制定新的并网准则对并网风电场的输出特性作出严格规定,并网导则中的一项重要内容是要求风电场具有低压穿越(LVRT)能力。电力电子技术是提高风电场低电压穿越能力的重要手段,对于变速风电机组,电力电子设备已成为其标准配置,在低电压穿越过程中起到至关重要的作用;对于定速风电机组,电力电子设备是使其满足并网导则的必要部件。本文以我国并网导则为例,介绍LVRT导则对风电机组输出特性的相关要求:分析电网电压跌落对不同类型风电机组的影响;在此基础上,针对不同类型的风电机组,介绍提高其LVRT能力的电力电子技术,并对LVRT技术中当前存在的问题和未来的发展方向进行了讨论。     

百年电子学--纪念真空电子管发明一百周年

电子学的崛起、发展和广泛应用是20世纪最伟大的科学技术领域之一.在电磁波理论和自由电子发展的基础上,1904年出现了第一只真空二极电子管,一般认为这标志着电子学的诞生.电磁波频谱资源的开发和利用是电子学发展的基础和动力.从电磁频谱统一的观点看,光已经象微波一样进入到电子学的领域,成为无线电电子学中不可分割的组成部分.电子学的基本任务是:研究带电粒子流与电磁场相互作用的物理概念和物理过程,以及利用相互作用的不同物理机制实现粒子与场之间能量有效转化的方法和条件.从电子器件的观点看,电子学可分为真空电子学与固态电子学;而从电子运动规律的观点看,现代电子学将处理自由电子,准自由电子和束缚电子的运动规律及其与电磁场的相互作用.1958年,电子学领域出现三个重要发现和发明:集成电路、激光和相对论自由电子的回旋辐射.相应的,半导体电子学(微电子学)、激光电子学和相对论电子学等现代电子学领域则发端于此.电子器件小型化、微型化、功能集成化将电磁频谱的开拓和占领推向光波和红外毫米波.