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Easy access to clean water is essential to functioning and development of modern society. However, it remains arduous to develop energy-efficient, facile, and portable water treatment systems for point-of-use (POU) applications, which is particularly imperative for the safety and resilience of society during extreme weather and critical situations. Here, we propose and validate a meritorious working scheme for water disinfection via directly capturing and removing pathogen cells from bulk water using strategically designed three-dimensional (3D) porous dendritic graphite foams (PDGFs) in a high-frequency AC field. The prototype, integrated in a 3D-printed portable water-purification module, can reproducibly remove 99.997% E. coli bacteria in bulk water at a few voltages with among the lowest energy consumption at 435.5 J·L -1 The PDGFs, costing $1.47 per piece, can robustly operate at least 20 times for more than 8 h in total without functional degradation. Furthermore, we successfully unravel the involved disinfection mechanism with one-dimensional Brownian dynamics simulation. The system is practically applied that brings natural water in Waller Creek at UT Austin to the safe drinking level. This research, including the working mechanism based on dendritically porous graphite and the design scheme, could inspire a future device paradigm for POU water treatment.. The PDGFs, costing $1.47 per piece, can robustly operate at least 20 times for more than 8 h in total without functional degradation. Furthermore, we successfully unravel the involved disinfection mechanism with one-dimensional Brownian dynamics simulation. The system is practically applied that brings natural water in Waller Creek at UT Austin to the safe drinking level. This research, including the working mechanism based on dendritically porous graphite and the design scheme, could inspire a future device paradigm for POU water treatment.

Abstract: The practical applications of wearable electronics rely on the successful development of flexible and integrable energy devices with small footprints. This work reports a completely new type of graphite foam made of strategically created superstructures with covalently attached diverging microtubes, and their applications as electrode supports for binder‐free and additive‐free flexible supercapacitors. Because of the enhanced volumetric surface areas compared to conventional graphite foams, a high loading of pseudocapacitive materials (Mn3O4, 3.91 mg cm−2, 78 wt%) is achieved. The supercapacitors provide areal capacitances as high as 820 mF cm−2 at 1 mV s−1, while still maintaining high rate capability and 88% retention of capacitance after 3000 continuous charging and discharging cycles. When assembled as all‐solid‐state flexible symmetric supercapacitors, they offer one of the highest full‐cell capacitances (191 mF cm−2) among similar manganese oxide/graphene foams, and retain 80% capacitance after 1000 mechanical cycles. The potential of such flexible supercapacitors is also manifested by directly powering electric nanomotors that can trace along letters “U” and T,” which is the first demonstration of flexible supercapacitors for wireless/portable nanomanipulation systems. This work could inspire a new paradigm in designing and creating 3D porous micro/nanosuperstructures for an array of self‐powered electronic and nanomechanical applications. [ABSTRACT FROM AUTHOR]

The design and fabrication of various types of flexible, portable, and foldable devices have received immense interest owing to the remarkable potential in impacting peoples' lives including real‐time health monitoring, point‐of‐care diagnosis, and athletic training. In this work, the authors present 3D graphite as the key sensing element of polymer composite strain sensors that offers ultrahigh sensitivity and durability in the detection of fine motions. The graphite–polymer sensors in this work provide high bending sensitivities that are reproducible within 3% signal shift after 11 000 bending cycles and exhibit gauge factors of 100 and 52 at tensile strains of 80% and 100%, respectively. The sensing mechanism is modeled, and correlated with experimental studies. The high strain sensitivity compared to graphene based devices is analyzed and understood with respect to levels of defect in materials. Such graphite–polymer sensors are able to detect fine features of human pulses, respiration rates, and throat vibration in real time and are also applied in the detection of posture correctness of musical instrument learners for the first time. [ABSTRACT FROM AUTHOR]