Exploration of wearable strain sensors in diverse application scenarios is one global requirement for shaping the future of our intelligent community. However, state-of-the-art wearable devices still face challenges such as interference under humid conditions and chemical/mechanical fragility. Here, a facile and fluorine-free approach is introduced to realize a sensitive, robust and superhydrophobic strain sensor via the in situ formation of microcilia on the PDMS surface, followed by a two-step swelling process. The swelling process facilitates the penetration of carbon black nanoparticles into the PDMS matrix to render the conductive network suitable for strain sensing, while the decoration of silica nanoparticles along with the microcilia forms a hierarchical architecture for water repellency. The sensing performance was optimized, including the sensitivity (gauge factor of 354), working range (up to 250%), and long-term stability (>10 000 cycles). The superhydrophobic surface exhibits excellent resistance to mechanical abrasion, chemical corrosion, and high-speed water impact, etc. Demonstrations, such as body motion perception, wireless and underwater communications, Morse code generation, underwater jet impact, reveal the potential of the sensor as a robust platform for broad applications not only in air but also for underwater or under harsh condition uses.

Manipulation of micro-objects have been playing an essential role in biochemical analysis or clinical diagnostics. Among the diverse technologies for micromanipulation, acoustic methods show the advantages of good biocompatibility, wide tunability, a label-free and contactless manner. Thus, acoustic micromanipulations have been widely exploited in micro-analysis systems. In this article, we reviewed the acoustic micromanipulation systems that were actuated by sub-MHz acoustic waves. In contrast to the high-frequency range, the acoustic microsystems operating at sub-MHz acoustic frequency are more accessible, whose acoustic sources are at low cost and even available from daily acoustic devices (e.g. buzzers, speakers, piezoelectric plates). The broad availability, with the addition of the advantages of acoustic micromanipulation, make sub-MHz microsystems promising for a variety of biomedical applications. Here, we review recent progresses in sub-MHz acoustic micromanipulation technologies, focusing on their applications in biomedical fields. These technologies are based on the basic acoustic phenomenon, such as cavitation, acoustic radiation force, and acoustic streaming. And categorized by their applications, we introduce these systems for mixing, pumping and droplet generation, separation and enrichment, patterning, rotation, propulsion and actuation. The diverse applications of these systems hold great promise for a wide range of enhancements in biomedicines and attract increasing interest for further investigation.

Ensuring accessible and high-quality healthcare worldwide requires field-deployable and affordable clinical diagnostic tools with high performance. In recent years, flexible electronics with wearable and implantable capabilities have garnered significant attention from researchers, which functioned as vital clinical diagnostic-assisted tools by real-time signal transmission from interested targets in vivo. As the most crucial and complex system of human body, cardiocerebral vascular system together with heart-brain network attracts researchers inputting profuse and indefatigable efforts on proper flexible electronics design and materials selection, trying to overcome the impassable gulf between vivid organisms and rigid inorganic units. This article reviews recent breakthroughs in flexible electronics specifically applied to cardiocerebral vascular system and heart-brain network. Relevant sensor types and working principles, electronics materials selection and treatment methods are expounded. Applications of flexible electronics related to these interested organs and systems are specially highlighted. Through precedent great working studies, we conclude their merits and point out some limitations in this emerging field, thus will help to pave the way for revolutionary flexible electronics and diagnosis assisted tools development.