Collagen Ucl Hafnia Regensburg Carbon Blend CrAu temperature controller AFM Butterfly Phase Current ULCA Polarization Logo single_layer Wonseok electrospinning NUS self_healing AEAPDES Optical I-VSpectroscopy Sapphire Cobalt self_assembly Silicon Iron Hafnium_dioxide OrganicCompound Ananth Annealing Strontium Worcester_Polytechnic_Institute Reduction sputter