Healthy subjects were recruited to represent a variety of ages, genders and cultural backgrounds. Ethics oversightAll procedures in the in vivo trials were performed in accordance with the experimental protocol approved by the Committee on the Use of Humans as Experimental Subjects of the Massachusetts Institute of Technology (COUHES Protocol 2101000301). The participants gave informed consent.Note that full information on the approval of the study protocol must also be provided in the manuscript.

Recent advancements in wearable technology have improved lifestyle and medical practices, enabling personalized care ranging from fitness tracking, to real-time health monitoring, to predictive sensing. Wearable devices serve as an interface between humans and technology; however, this integration is far from seamless. These devices face various limitations such as size, biocompatibility, and battery constraints wherein batteries are bulky, are expensive, and require regular replacement. On-body energy harvesting presents a promising alternative to battery power by utilizing the human body's continuous generation of energy. This review paper begins with an investigation of contemporary energy harvesting methods, with a deep focus on piezoelectricity. We then highlight the materials, configurations, and structures of such methods for self-powered devices. Here, we propose a novel combination of thin-film composites, kirigami patterns, and auxetic structures to lay the groundwork for an integrated piezoelectric system to monitor and sense. This approach has the potential to maximize energy output by amplifying the piezoelectric effect and manipulating the strain distribution. As a departure from bulky, rigid device design, we explore compositions and microfabrication processes for conformable energy harvesters. We conclude by discussing the limitations of these harvesters and future directions that expand upon current applications for wearable technology. Further exploration of materials, configurations, and structures introduce interdisciplinary applications for such integrated systems. Considering these factors can revolutionize the production and consumption of energy as wearable technology becomes increasingly prevalent in everyday life.

Ultrasound is widely used for tissue imaging such as breast cancer diagnosis; however, fundamental challenges limit its integration with wearable technologies, namely, imaging over large-area curvilinear organs. We introduced a wearable, conformable ultrasound breast patch (cUSBr-Patch) that enables standardized and reproducible image acquisition over the entire breast with less reliance on operator training and applied transducer compression. A nature-inspired honeycomb-shaped patch combined with a phased array is guided by an easy-to-operate tracker that provides for large-area, deep scanning, and multiangle breast imaging capability. The in vitro studies and clinical trials reveal that the array using a piezoelectric crystal [Yb/Bi-Pb(In 1 /2 Nb 1/2 )O 3 -Pb(Mg 1/ 3 Nb 2/3 )O 3 -PbTiO 3 ] (Yb/Bi-PIN-PMN-PT) exhibits a sufficient contrast resolution (~3 dB) and axial/lateral resolutions of 0.25/1.0 mm at 30 mm depth, allowing the observation of small cysts (~0.3 cm) in the breast. This research develops a first-of-its-kind ultrasound technology for breast tissue scanning and imaging that offers a noninvasive method for tracking real-time dynamic changes of soft tissue.

Purpose Although conformable devices are commonly designed to couple with the human body for personalized and localized medicine, their applications are expanding rapidly. This paper aims to delineate this expansion and predict greater implications in diverse fields. Design/methodology/approach Today’s device technologies continue to face fundamental obstacles preventing their seamless integration with target objects to effectively access, evaluate and alter self-specific physical patterns, while still providing physical comfort and enabling continuous data collection. Due to their extreme mechanical compliance, conformable devices permit the query of signals occurring at interfaces so as to decode and encode biological, chemical and mechanical patterns with high resolution, precision and accuracy. These unique and versatile capabilities allow for a marked change in the approach to tackling scientific questions, with the ability to address societal challenges at large. Findings Here, this study highlights the current state of these devices in a wide range of fields, such as interactive teaching, textiles, robotics, buildings and infrastructure, agriculture, climate and space, and further forecasts essential features of these devices in the near future. Originality/value This study justifies conformable devices’ growing utility through a novel quantitative analysis methodology that indexes peer-reviewed journal articles based on specific keywords, whereby this study tracks keyword frequency over time across specific fields in conjunction with conformability-like topics. The resulting trends’ trajectories provide the foundation for this study’s future projections. This study concludes with a perspective on the possible challenges concomitant with a ubiquitous presence of these technologies, including manufacturing, wireless communication, storage, compression, privacy and sharing of data, environmental sustainability, avoidance of inequality and bias and collaboration between stakeholders at all levels of impact.