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Sustainable shape-memory and self-healing elastomers with semi-interpenetrating network were prepared by a simple, efficient, and green bulk radical polymerization of ethyl cellulose, furfural, and fatty-acid-derived monomers. This approach could in situ one-pot form a semi-interpenetrating network elastomer with properties combining multiple-shape-memory and self-healing under solvent-free conditions. These elastomers were found to possess excellent multiple-shape-memory properties toward temperature, water, THF, and methanol. Moreover, the multiple-shape-memory properties could assist the self-healing of these elastomers, which was triggered by heating. Self-healing behavior studies showed that the presence of linear polymers in these elastomers could significantly improve the self-healing performance. This work provides a facile, efficient, and green approach in a solvent-free system to design new-generation sustainable, green, and functional materials.

In this paper, we address the problem of controlling networks of wireless mobile nodes to propagate information over large distances, while minimizing power consumption and maintaining desired Quality of Service (QoS) guarantees. For this, we rely on collaborative beamforming, where groups of nodes collaborate to adjust the initial phase of their transmitted signals to form a beam that focuses on the direction of a desired destination. This allows for transmission over large distances, minimizes multiuser interference and also provides significant power savings, which increases network longevity. Beamforming has been thoroughly studied in the networking literature in the context of stationary antennas. The contribution of this work is a novel framework that jointly optimizes the beamforming weights and node positions in networks of mobile beamformers. In particular, a hybrid control scheme is proposed, in which optimal beamforming is integrated with potential-field-based motion control, designed to optimize power consumption in the space of node positions, while ensuring QoS. The integrated system is shown to exhibit superior performance in terms of power savings compared to approaches that do not consider node mobility. This makes our approach very promising for further research and applications in mobile wireless networks.

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