Stacking of incorrectly-folded protein molecules has profound medical implications, as it has been associated with a number of fatal disorders such Alzheimer disease. From the physicochemical perspective, however, the linear aggregation (fibrillation) reflects a common generic feature of proteins as polyamides. Therefore the aggregation can be induced in benign proteins, as well. I am showing how dynamics and structural variability of aggregating proteins may inspire novel strategies in engineering of molecular devices. Aggregation of insulin molecules under high hydrostatic pressure yields uniquely regular nanorings. On the other hand, high specificity of the docking interactions between incoming protein monomers and fibrils' termini (during the elongation process) may translate into the possibility of employing fibrils as selective protein receptors. As growth of protein fibrils may be triggered by seeding, and the conformational pattern of the template easily overrides environmental biases, it is now possible to obtain highly homogenous (in terms of morphology) samples of the fibrils. Several applications of aggregating insulin molecules, and sequenceless polypeptide chains for nano-drug-delivery, and pH-controllable ‘molecular Velcro’, respectively, will be demonstrated. Such novel bionanosystems may be easily transformed into smart enzymes and/or antibodies layers for a renewable immobilization atop biosensors and biochips.