Skin is a rich source of invaluable information for healthcare management and disease diagnostics. The integration of soft skin electronics enables precise and timely capture of these cues at the skin interface. Leveraging attributes such as lightweight design, compact size, high integration, biocompatibility, and enhanced comfort, these technologies hold significant promise for advancing various applications. However, the fabrication process for most existing soft skin electronics typically requires expensive platforms and clean-room environments, potentially inflating production costs. In recent years, the emergence of laser-induced-graphene (LIG) has presented a practical solution for developing soft skin electronics that are both cost-effective and high-performing. This advancement paves the way for the widespread adoption of intelligent healthcare technologies. Here, we comprehensively review recent studies focusing on LIG-based soft skin electronics (LIGS2E) for intelligent healthcare applications. We first outline the preparation methodologies, fundamental properties of LIG, and standard regulation strategies employed in developing soft skin electronics. Subsequently, we present an overview of various LIGS2E designs and their diverse applications in intelligent healthcare. These applications encompass biophysical and biochemical sensors, bio-actuators, and power supply systems. Finally, we deliberate on the potential challenges associated with the practical implementation of LIGS2E in healthcare settings and offer insights into future directions for research and development. By elucidating the capabilities and limitations of LIGS2E, this review aims to contribute to advancing intelligent healthcare technologies.
The utilization of hydrogels in soft electronics has led to significant progress in the field of wearable and implantable devices. However, challenges persist in hydrogel electronics, including the delicate equilibrium between stretchability and electrical conductivity, intricacies in miniaturization, and susceptibility to dehydration. Here, a lignin‐polyacrylamide (Ag‐LPA) hydrogel composite endowed with anti‐freeze, self‐adhesive, exceptional water retention properties, and high stretchability (1072%) is presented. Notably, this composite demonstrated impressive electrical conductivity at room temperature (47.924 S cm−1) and extremely cold temperatures (42.507 S cm−1). It is further proposed for microfluidic‐assisted hydrogel patches (MAHPs) to facilitate customizable designs of the Ag‐LPA hydrogel composite. This approach enhances water retention and offers versatility in packaging materials, making it a promising choice for enduring soft electronics applications. As a proof‐of‐concept, soft electronics across diverse applications and dimensions, encompassing healthcare monitoring, environmental temperature sensing, and 3D‐spring pressure monitoring electronics are successfully developed. The scenery of an extremely cold environment is further extended. The conductivity of the embedded Ag‐LPA hydrogel composite unveils the potential of MAHPs in polar rescue missions. It is envisioned that MAHPs will impact the development of sophisticated and tailored soft electronics, thereby forging new frontiers in engineering applications.
Multiplexed biosensing methods for simultaneously detecting multiple biomolecules are important for investigating biological mechanisms associated with physiological processes, developing applications in life sciences, and conducting medical tests. The development of biosensors, especially those advanced biosensors with multiplexing potentials, strongly depends on advancements in nanotechnologies, including the nano-coating of thin films, micro–nano 3D structures, and nanotags for signal generation. Surface functionalization is a critical process for biosensing applications, one which enables the immobilization of biological probes or other structures that assist in the capturing of biomolecules. During this functionalizing process, nanomaterials can either be the objects of surface modification or the materials used to modify other base surfaces. These surface-functionalizing strategies, involving the coordination of sensor structures and materials, as well as the associated modifying methods, are largely determinative in the performance of biosensing applications. This review introduces the current studies on biosensors with multiplexing potentials and focuses specifically on the roles of nanomaterials in the design and functionalization of these biosensors. A detailed description of the paradigms used for method selection has been set forth to assist understanding and accelerate the application of novel nanotechnologies in the development of biosensors.
Fish can perceive the surrounding flow field using their lateral line systems, consisting of canal neuromasts (CNs) for flow pressure gradient perception and superficial neuromasts (SNs) for flow velocity detection. Although various artificial lateral line (ALL) systems have been developed inspired by the lateral line of fish, few studies have combined both pressure and velocity sensors for hydrodynamic perception, and how to optimize sensor placement remains unanswered, particularly on three-dimensional models. Herein we proposed a maximized hydrodynamic stimulation strategy for sensor placement optimization. We built a fish model and designed an ALL system by mimicking the geometry of a blind cavefish, Sinocyclocheilus tianlinensis . Differential pressure sensors and hot-film flow velocity sensors were used to mimic the CNs and SNs, respectively, with optimized sensor placement. The simulation and experimental results on yaw angle detection suggested that both sensor placement of our ALL system and distribution of the biological lateral line showed good agreement with the maximized hydrodynamic stimulation strategy. Our ALL system could detect a wall within a distance of 0.1 body length, comparable to the perception ability of cave fish. The new sensor placement strategy can be used to equip ALL systems on bionic robotic fish and other underwater vehicles.