E‐waste is rapidly turning into another man‐made disaster. It is proposed that a paradigm shift toward a more sustainable future can be made through soft‐matter electronics that are resilient, repairable if damaged, and recyclable (3R), provided that they achieve the same level of maturity as industrial electronics. This includes high‐resolution patterning, multilayer implementation, microchip integration, and automated fabrication. Herein, a novel architecture of materials and methods for microchip‐integrated condensed soft‐matter 3R electronics is demonstrated. The 3R function is enabled by a biphasic liquid metal‐based composite, a block copolymer with nonpermanent physical crosslinks, and an electrochemical technique for material recycling. In addition, an autonomous laser‐patterning method for scalable circuit patterning with an exceptional resolution of <30 µm in seconds is developed. The phase‐shifting property of the BCPs is utilized for vapor‐assisted “soldering” circuit repairing and recycling. The process is performed entirely at room temperature, thereby opening the door for a wide range of heat‐sensitive and biodegradable polymers for the next generation of green electronics. The implementation and recycling of sophisticated skin‐mounted patches with embedded sensors, electrodes, antennas, and microchips that build a digital fingerprint of the human electrophysiological signals is demonstrated by collecting mechanical, electrical, optical, and thermal data from the epidermis.
Magnetite nanoparticles were synthesized by the co-precipitation method with and without the assistance of an additive, namely, gelatin, agar-agar or pectin, using eco-friendly conditions and materials embodying a green synthesis process. X-ray diffraction and transmission electron microscopy were used to analyze the structure and morphology of the nanoparticles. Magnetic properties were investigated by SQUID magnetometry and 57Fe Mössbauer spectroscopy. The results show that the presence of the additives implies a higher reproducibility of the morphological magnetic nanoparticle characteristics compared with synthesis without any additive, with small differences associated with different additives. To assess their potential for magnetic hyperthermia, water-based suspensions of these nanoparticles were prepared with and without citric acid. The stable solutions obtained were studied for their structural, magnetic and heating efficiency properties. The results indicate that the best additive for the stabilization of a water-based emulsion and better heating efficiency is pectin or a combination of pectin and agar-agar, attaining an intrinsic loss power of 3.6 nWg−1.