Biomimetic polymers and their characterization: toward sustainable materials using synthetic biology

Biomimetic polymers have emerged as a powerful class of materials that are capable of replicating biological processes, functions, properties, or structures found in natural systems. While extensive reviews are available due to the significant progress in synthetic biomimetic materials, this review focuses exclusively on sustainable, naturally derived biomimetic polymers, as the global focus has shifted towards low-carbon footprint remedies. Biomimicry can only be reliably evaluated using appropriate characterization techniques, and selecting the ideal technique depends on several factors: the specific biomimetic feature of interest, the relevant length scale, the condition of the sample, and whether qualitative or quantitative assessment is required. Hence, we critically survey how complementary chemical, mechanical, structural, and morphological methods are able to span different length scales. We highlight both established and emerging characterization techniques which belong to four broad categories: spectroscopy, microscopy, diffraction/scattering, and thermo-mechanical analysis. Ultimately, this review guides the rational design for next-generation biomimetic materials, bridging the gap between biomimicry, material characterization, and sustainable materials.