No abstract

Flexible electronics are drawing tremendous interest for various applications in wearable healthcare biomonitoring, on-demand therapy, and humanmachine interactions. However, conventional plastic substrates with uncomfortableness, mechanical mismatches, and impermeability have limited the application of flexible on-skin electronic devices for healthcare biomonitoring and on-demand therapy. Herein, flexible breathable electronic devices with the capabilities of real-time temperature sensing and timely on-demand antiinfection therapy at wound sites are presented. These devices are assembled from a crosslinked electrospun moxifloxacin hydrochloride (MOX)-loaded thermoresponsive polymer nanomesh film with a conductive pattern. The conductive polymer nanomesh film demonstrates excellent flexibility, reliable breathability, and robust environmental stability. Furthermore, the assembled temperature sensor displays a linear relationship between the electrical resistance and temperature, potentially enabling real-time biomonitoring of tissue temperature at the wound site. Smart artificial electronic skins (E-skins) are assembled from the thermoresponsive polymer nanomesh film for spatial touching sensing mapping of temperature changes. Furthermore, the flexible temperature sensor is coupled with a wireless transmitter for real-time wireless temperature monitoring. Notably, the thermoresponsive polymer nanomesh film can also be assembled as a highly efficient flexible heater to trigger the on-demand release of antibiotics loaded in the fibers to eliminate bacterial colonization in the wound site once infection has occurred.

We present a strategy to fabricate polymer solar cells in inverted geometry by self-organization of alcohol soluble cathode interfacial materials in donor-acceptor bulk heterojunction blends. An amine-based fullerene [6,6]-phenyl-C61-butyric acid 2-((2-(dimethylamino)-ethyl)(methyl)amino)ethyl ester (PCBDAN) is used as an additive in poly(3-hexylthiophene) (P3HT) and 6,6-phenyl C61-butyric acid methyl ester (PCBM) blend to give a power conversion efficiency of 3.7% based on devices ITO/P3HT:PCBM:PCBDAN/MoO3/Ag where the ITO alone is used as the cathode. A vertical phase separation in favor of the inverted device architecture is formed: PCBDAN is rich on buried ITO surface reducing its work function, while P3HT is rich on air interface with the hole-collecting electrode. The driving force of the vertical phase separation is ascribed to the surface energy and its components of the blend compositions and the substrates. Similar results are also found with another typical alcohol soluble cathode interfacial materials, poly[(9,9-bis(3'-(N, N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN), implying that self-organization may be a general phenomenon in ternary blends. This self-organization procedure could eliminate the fabrication of printing thin film of interlayers or printing on such thin interlayers and would have potential application for roll-to-roll processing of polymer solar cells.