Proton-conducting materials play a central role in many renewable energy and bioelectronics technologies, including fuel cells, batteries and sensors. Thus, much research effort has been expended to develop improved proton-conducting materials, such as ceramic oxides, solid acids, polymers and metal-organic frameworks. Within this context, bulk proton conductors from naturally occurring proteins have received somewhat less attention than other materials, which is surprising given the potential modularity, tunability and processability of protein-based materials. Here, we report proton conductivity for thin films composed of reflectin, a cephalopod structural protein. Bulk reflectin has a proton conductivity of ~2.6 × 10(-3) S cm(-1) at 65 °C, a proton transport activation energy of ~0.2 eV and a proton mobility of ~7 × 10(-3) cm(2) V(-1) s(-1). These figures of merit are similar to those reported for state-of-the-art artificial proton conductors and make it possible to use reflectin in protein-based protonic transistors. Our findings may hold implications for the next generation of biocompatible proton-conducting materials and protonic devices.

In nature, cephalopods employ unique dynamic camouflage mechanisms. Herein, we draw inspiration from self‐assembled structures found in cephalopods to fabricate tunable biomimetic camouflage coatings. The reflectance of these coatings is dynamically modulated between the visible and infrared regions of the electromagnetic spectrum in situ. Our studies represent a crucial step towards reconfigurable and disposable infrared camouflage for stealth applications.

Background: synGAP inactivates Ras and Rap at synapses. Results: Phosphorylation of synGAP by CaMKII increases Rap1 GAP activity more than HRas GAP activity; phosphorylation by CDK5 has the opposite effect. Conclusion: Phosphorylation by CaMKII and CDK5 alters the ratio of Rap1 and HRas GAP activities. Significance: Phosphorylation of synGAP by CaMKII and CDK5 can alter the balance of synaptic functions regulated by Ras and Rap.

The skin morphology of cephalopods endows them with remarkable camouflage capabilities. Herein, we report infrared invisibility stickers inspired by the structures and proteins found in cephalopod skin. These stickers enable arbitrary objects to acquire reconfigurable infrared camouflage patterning. Our work represents an initial step towards wearable biomimetic infrared stealth technologies.