Over the past decades, wearable and implantable devices have demonstrated great potential for a wide range of personalized health monitoring and therapeutic applications. This special issue primarily focuses on functional and electronic materials, sensors technologies and capabilities, and the associated energy solutions for wearable and implantable devices toward healthcare applications. We have collected 17 reviews, four research articles, and one perspective, all of which are within the scope of this area and cover the topics in breadth and depth.

Functional materials with reduced dimensions, such as nanomaterials, have unique properties to match with or to allow seamless integration with soft deformable tissues and organs, and/or to provide unique interfaces for sensing and therapeutic functions. Woon-Hong Yeo and co-workers summarize the recent progress and advances in various organic and inorganic nanomaterials and additive printing technologies for the development of soft, bioresorbable devices (article number 2100158). Nanomaterials, ranging from nanoparticles, to nanofibers, to nanomembranes, and to hydrogels, offer advantages in intimate interfaces, low impedance in sensing, biocompatibility, and degradability. Different printing technologies such as screen printing, inkjet printing, aerosol jet printing, and laser sintering for manufacturing implantable devices are also discussed.

Owing to their low moduli, deformability, and processability, elastomers and polymers are an important class of materials for the construction of soft and bio-integrated electronics to form a conformal interface with soft and curvilinear biological tissues. Dae-Hyeong Kim and co-workers provide an overview of conductive elastomers, semiconducting elastomers, adhesive elastomers, and self-healing elastomers and their usages in building these soft and bio-integrated electronics (article number 2002105). Zhenan Bao and co-workers summarize the progress of various conjugated polymers, including semiconducting polymers and conducting polymers, and the design considerations of these polymers in various implantable neural interface devices (article number 2001916). Among many devices, soft electrodes are one of the most critical devices for both non-invasive and invasive electrophysiological signal recording. Yingying Zhang and co-workers discuss various soft, flexible electrodes in wires, meshes, and film formats as wearables and implants (article number 2100646). Wenlong Cheng and co-workers provide an overview of the soft materials and deformable microstructure design strategies of the future soft healthcare devices. Recent progress of the soft wearable healthcare devices for continuous monitoring physical, electrophysiological, chemical, and biological signals is also discussed (article number 2100577).

The intrinsic stretchability and high conductivity of liquid metals make them a promising candidate for designing bio-interfaced electronics. Yang-Ung Park et al. review the featured properties and processing technologies of liquid metal-based soft wearable electronics. Example applications on biosensors, soft interconnects, and neural interfaces are discussed along with the challenges and prospects for future development (article number 2002280). Biological materials are another promising candidate in the development of wearable electronics as they are abundant, sustainable, biocompatible, and biodegradable. Tae-Woo Lee and co-workers summarize the biomaterials and structures used in wearable pressure sensors based on various sensing mechanisms such as piezoelectric, triboelectric, piezoresistive and capacitive effects (article number 2100460). Considering that transient materials are attracting growing interest for temporary biomedical implants, John A. Rogers and co-workers highlight recent advances in the development of implantable devices made of bioresorbable metals and metal alloys toward diagnostic and therapeutic applications (article number 2002236).

This special issue also features multiple research articles reporting novel conductive materials and devices for reliable, robust and high fidelity soft, wearable sensors. George Malliaras and co-workers report the development of mm pitch-size surface electromyography arrays from composites of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) with the biocompatible ionic liquid (IL), cholinium lactate, to allow the high quality spatiotemporal recordings of forearms motions and activities (article number 2100374). Benjamin Chee Keong Tee and co-workers describe a new conductor of eHelix, a highly stretchable and reliable conductor composite made from helical copper wires and a soft elastomer, with robust and deformation-insensitive electrical conductivity (article number 2100221). The eHelix was successfully employed and validated its usages in several different devices, including wearable smart fabrics, a heart rate monitor, and a tactile sensing glove.

While there are lots of recent advances in materials and device innovations toward wearable and implantable sensors and electronics, the ultimate sensing and continuous monitoring call for sustainable, bio-compatible, or battery-free medical devices. Seung Hwan Ko et al. summarize the progress of batteryless, wearable devices based on a variety of non-battery energy sources, such as electromagnetic energy, mechanical energy, biofuels, triboelectricity, thermoelectricity and wireless power transfer (article number 2002286). The power solution is even more critical and challenging in implantable devices compared with wearables. Wei Lan and co-workers outline the different energy sources, including 1) energy storage devices of batteries and supercapacitors; 2) energy-harvesting devices of biofuel cells, piezoelectric and triboelectric energy harvesters, thermoelectric and biopotential power generators; and 3) wireless power transfer devices based on inductive coupling, ultrasound, and photovoltaics (article number 2100199).

In particular, wireless power transfer is considered to be favorable for many implantable devices. Jacob Robinson and co-workers review six different types of widely reported wireless power transfer technologies in implants, including inductive coupling, radiofrequency, mid-field, ultrasound, magnetoelectrics, and light (article number 2100664). Different technologies are summarized with respect to several critical tradeoffs or design considerations in power, miniaturization, depth, alignment tolerance, transmitter distance, and safety. In another review article, Dae-Hyeong Kim and co-workers summarize the recent advances in RF-based wireless power transfer and telemetry (for physiological data acquisition) for implantable bioelectronics to address the challenges resulted from the constraint and requirement for in vivo operation (article number 2100614). Michael A. Daniele and co-workers provide a review of the state-of-the-art ultrasound-powered implants as a promising wireless power transfer (article number 2100986). Different piezoelectric materials and harvesting devices including lead-based inorganic, lead-free inorganic, and organic polymers are summarized and their performance metrics and applications are presented.

One key advantage of soft, flexible and wearable sensors is that they are capable of continuously tracking physiological parameters that are closely linked to an individual's health state. One key example application is cardiac activity monitoring to mitigate the incidence of and mortality caused by cardiovascular diseases. Chwee Teck Lim and co-workers provide an overview of recent progress in the development of flexible wearable sensors for personalized monitoring of cardiovascular biomarkers including electrocardiography, heart rate, blood pressure, blood oxygen saturation, and blood glucose (article number 2100116). Given the critical role of systolic and diastolic blood pressure monitoring for guiding clinical decision-making in the pediatric intensive care unit, the application of soft skin-interfaced wearable devices (optimized by careful selection of materials and mechanical designs) for wireless continuous tracking of systolic and diastolic blood pressure on pediatric patients is demonstrated by John A. Rogers et al. (article number 2100383). In addition to cardiac activities, wearable sensors can also be applied to monitor a number of biomarkers including humidity, temperature, as well as muscle and brain activities. An integrated wearable and flexible system consisting of a ZnIn₂S₄ nanosheet-based humidity sensor and a carbon nanotube/SnO₂ temperature sensor is presented by Kuniharu Takei and co-workers and successfully evaluated on healthy volunteers to investigate the thermoregulatory responses under cold stimulation and exercise toward potential early prediction of thermoregulation disorders in the human body (article number 2100103).

While commercially available wearable devices and most current research efforts are focused on monitoring health-related physical parameters, continuous tracking of molecules represents a major gap and opportunity to reveal a full picture of health. Joseph Wang and co-workers review the current progress, emerging trends, and unmet challenges of using microneedles as a minimally-invasive and effective means to access interstitial fluid for real-time monitoring of metabolites, electrolytes, and drugs (article number 2002255). Continuous monitoring of bodily fluid biomarkers could enable personalized medicine by tailoring therapeutics according to the real-time collected biomarker information. A great example here is closed-loop diabetes care in which one can tune the drug delivery based on the blood glucose levels. With a focus on materials and construction, Chi Hwan Lee summarize the recent innovations of wearable glucose monitoring and implantable insulin delivery approaches toward improved personalized diabetes management (article number 2100194).

Successful translation of current proof-of-concept wearable and implantable technologies requires extensive human studies. In a perspective article, Wei Gao and co-workers present relevant ethical concerns on various aspects of early-stage human research (including reliability and validity, risk assessment, subject selection, data privacy and security, and informed consent) to evaluate the wearable prototypes from a researcher's perspective (article number 2100127). Machine learning is a promising approach to analyze and process the large sets of physiological data collected by the wearable biosensors from human studies. Xiaodong Chen and co-workers summarize different types of non-invasive biosensors and physiological signals collected from the human body, and review the machine learning algorithms used in data processing toward practical clinical practice and public health applications (article number 2100734). One could expect that, with further technological developments coupled with ethically conducted human validation, wearable and implantable devices could be readily applicable for both medical diagnosis and daily health monitoring in tackling a number of health conditions.

This collection of reviews, research articles, and perspective in this special issue clearly show the fast advancement in materials and device technologies and also their usages and impacts in many clinical applications. Yet, as the past decade witnessed drastic advancement in this field, this collection only presents a small fraction of them. We expect that this special issue will spur a broader research community of science, engineering, biology, and medicine to join forces toward further, continuous development and innovations in the years to come.

We would like to express our gratitude to all authors for their efforts and hard work to make this special issue possible. We also would like to thank those who we have not been able to include here due to the volume limitation of this special issue. Our deep appreciation finally goes to Dr. Irem Bayindir-Buchhalter and Dr. Conor Doss for their insights in recognizing the importance of this special issue topic, and all Wiley-VCH staff for their endless support in the editorial process.

在过去的几十年里，可穿戴和可植入设备在广泛的个性化健康监测和治疗应用方面表现出了巨大的潜力。本期特刊主要关注功能和电子材料、传感器技术和功能，以及面向医疗保健应用的可穿戴和可植入设备的相关能源解决方案。我们收集了 17 篇评论、4 篇研究文章和一个观点，所有这些都在该领域的范围内，涵盖了广度和深度的主题。

尺寸减小的功能材料，例如纳米材料，具有独特的特性，可以与柔软的可变形组织和器官匹配或允许无缝集成，和/或为传感和治疗功能提供独特的接口。Woon-Hong Yeo 及其同事总结了各种有机和无机纳米材料以及用于开发软生物可吸收设备的增材印刷技术的最新进展和进展（文章编号 2100158）。纳米材料，从纳米粒子到纳米纤维，再到纳米膜，再到水凝胶，在紧密界面、传感低阻抗、生物相容性和可降解性方面具有优势。还讨论了用于制造植入式器械的不同印刷技术，如丝网印刷、喷墨印刷、气溶胶喷射印刷和激光烧结。

由于它们的低模量、可变形性和可加工性，弹性体和聚合物是一类重要的材料，用于构建软和生物集成电子产品，以与软和曲线生物组织形成共形界面。Dae-Hyeong Kim 及其同事概述了导电弹性体、半导体弹性体、粘性弹性体和自愈弹性体及其在构建这些软生物集成电子产品中的用途（文章编号 2002105）。包哲南及其同事总结了各种共轭聚合物的进展，包括半导体聚合物和导电聚合物，以及这些聚合物在各种植入式神经接口装置中的设计考虑（文章编号2001916）。在众多设备中，软电极是非侵入性和侵入性电生理信号记录的最关键设备之一。Yingying Zhang 和同事讨论了作为可穿戴设备和植入物的各种线状、网状和薄膜形式的柔软、柔性电极（文章编号 2100646）。Wenlong Cheng 和同事概述了未来软医疗器械的软材料和可变形微结构设计策略。还讨论了用于连续监测物理、电生理、化学和生物信号的软可穿戴医疗保健设备的最新进展（文章编号 2100577）。Wenlong Cheng 和同事概述了未来软医疗器械的软材料和可变形微结构设计策略。还讨论了用于连续监测物理、电生理、化学和生物信号的软可穿戴医疗保健设备的最新进展（文章编号 2100577）。Wenlong Cheng 和同事概述了未来软医疗器械的软材料和可变形微结构设计策略。还讨论了用于连续监测物理、电生理、化学和生物信号的软可穿戴医疗保健设备的最新进展（文章编号 2100577）。

液态金属固有的可拉伸性和高导电性使其成为设计生物界面电子产品的有希望的候选者。Yang-Ung Park 等。回顾液态金属基软可穿戴电子产品的特性和加工技术。讨论了生物传感器、软互连和神经接口的示例应用以及未来发展的挑战和前景（文章编号 2002280）。生物材料是可穿戴电子产品开发的另一个有前途的候选材料，因为它们丰富、可持续、生物相容和可生物降解。Tae-Woo Lee 及其同事总结了基于压电、摩擦电、压阻和电容效应等各种传感机制的可穿戴压力传感器中使用的生物材料和结构（文章编号 2100460）。

本期特刊还刊登了多篇研究文章，报道了用于可靠、坚固和高保真柔软可穿戴传感器的新型导电材料和设备。George Malliaras 及其同事报告了由聚（3,4-亚乙基二氧噻吩）聚苯乙烯磺酸盐（PEDOT：PSS）与生物相容性离子液体（IL）、乳酸胆碱的复合材料开发的毫米间距大小的表面肌电图阵列，以允许前臂运动和活动的高质量时空记录（文章编号 2100374）。Benjamin Chee Keong Tee 及其同事描述了一种新型 eHelix 导体，这是一种高度可拉伸且可靠的导体复合材料，由螺旋铜线和柔软的弹性体制成，具有坚固且对变形不敏感的导电性（文章编号 2100221）。

虽然最近在可穿戴和可植入传感器和电子设备的材料和设备创新方面取得了许多进展，但最终的传感和持续监测需要可持续、生物兼容或无电池的医疗设备。Seung Hwan Ko 等人 总结了基于各种非电池能源的无电池、可穿戴设备的进展，例如电磁能、机械能、生物燃料、摩擦电、热电和无线电力传输（文章编号 2002286）。与可穿戴设备相比，电源解决方案在可植入设备中更为关键和更具挑战性。Wei Lan 和同事概述了不同的能源，包括 1) 电池和超级电容器的储能装置；2）生物燃料电池的能量收集装置，压电和摩擦电能收集器、热电和生物电势发电机；3) 基于电感耦合、超声波和光伏的无线电力传输设备（文章编号 2100199）。

特别是，无线电力传输被认为有利于许多可植入设备。Jacob Robinson 及其同事回顾了六种广泛报道的植入物无线电能传输技术，包括电感耦合、射频、中场、超声波、磁电和光（文章编号 2100664）。针对功率、小型化、深度、对准容差、发射器距离和安全性方面的几个关键权衡或设计考虑因素，总结了不同的技术。在另一篇评论文章中，Dae-Hyeong Kim 及其同事总结了用于植入式生物电子学的基于 RF 的无线电力传输和遥测（用于生理数据采集）的最新进展，以解决因体内操作的限制和要求而导致的挑战（文章编号 2100614）。Michael A. Daniele 及其同事对最先进的超声波动力植入物作为一种有前途的无线电力传输进行了评论（文章编号 2100986）。总结了不同的压电材料和收集装置，包括铅基无机、无铅无机和有机聚合物，并介绍了它们的性能指标和应用。

柔软、灵活且可穿戴的传感器的一个关键优势是它们能够持续跟踪与个人健康状况密切相关的生理参数。一个关键的应用示例是心脏活动监测，以降低心血管疾病的发病率和死亡率。Chwee Teck Lim 及其同事概述了开发用于个性化心血管生物标志物监测的柔性可穿戴传感器的最新进展，包括心电图、心率、血压、血氧饱和度和血糖（文章编号 2100116）。鉴于收缩压和舒张压监测在指导儿科重症监护室临床决策方面的关键作用，John A. Rogers 等人展示了软皮肤接口可穿戴设备（通过精心选择材料和机械设计进行优化）用于无线连续跟踪儿科患者的收缩压和舒张压的应用。（货号 2100383）。除了心脏活动，可穿戴传感器还可用于监测多种生物标志物，包括湿度、温度以及肌肉和大脑活动。由 ZnIn 组成的集成可穿戴和柔性系统 可穿戴传感器还可用于监测多种生物标志物，包括湿度、温度以及肌肉和大脑活动。由 ZnIn 组成的集成可穿戴和柔性系统 可穿戴传感器还可用于监测多种生物标志物，包括湿度、温度以及肌肉和大脑活动。由 ZnIn 组成的集成可穿戴和柔性系统 Kuniharu Takei 及其同事提出了 基于₂ S ₄纳米片的湿度传感器和碳纳米管/SnO ₂温度传感器，并成功地对健康志愿者进行了评估，以研究冷刺激和运动下的体温调节反应，从而对体温调节障碍进行潜在的早期预测人体（货号 2100103）。

虽然商用可穿戴设备和当前大多数研究工作都集中在监测与健康相关的物理参数上，但对分子的持续跟踪代表了揭示健康全貌的主要差距和机会。Joseph Wang 及其同事回顾了使用微针作为获取组织液实时监测代谢物、电解质和药物的微创有效手段的当前进展、新兴趋势和未解决的挑战（文章编号 2002255）。体液生物标志物的持续监测可以通过根据实时收集的生物标志物信息定制治疗方法来实现个性化医疗。这里的一个很好的例子是闭环糖尿病护理，其中可以根据血糖水平调整药物输送。

当前概念验证可穿戴和可植入技术的成功转化需要广泛的人体研究。在一篇观点文章中，Wei Gao 和同事提出了早期人类研究各个方面（包括可靠性和有效性、风险评估、受试者选择、数据隐私和安全以及知情同意）的相关伦理问题，以评估可穿戴原型从研究人员的角度来看（文章编号 2100127）。机器学习是一种很有前途的方法，可以分析和处理由可穿戴生物传感器从人类研究中收集的大量生理数据。陈晓东和同事总结了从人体采集到的不同类型的非侵入性生物传感器和生理信号，并回顾在面向实际临床实践和公共卫生应用的数据处理中使用的机器学习算法（文章编号 2100734）。人们可以预期，随着技术的进一步发展以及符合伦理的人体验证，可穿戴和可植入设备可以很容易地适用于医疗诊断和日常健康监测，以应对多种健康状况。

本期特刊中收集的评论、研究文章和观点清楚地表明了材料和设备技术的快速发展及其在许多临床应用中的用途和影响。然而，由于过去十年见证了该领域的巨大进步，本系列仅展示了其中的一小部分。我们预计，这一特刊将在未来几年激发更广泛的科学、工程、生物学和医学研究界的力量，共同迈向进一步、持续的发展和创新。

我们要感谢所有作者的努力和辛勤工作，使这期特刊成为可能。我们还要感谢那些由于本期特刊的数量限制而无法在此包括在内的人。最后，我们深切感谢 Irem Bayindir-Buchhalter 博士和 Conor Doss 博士对这一特刊主题重要性的洞察，以及所有 Wiley-VCH 员工在编辑过程中给予的无尽支持。