With a little help from nature: Generating steam through polypyrrole-coated bamboo

By: Esli Diepenbroek

Time has proven again and again that mankind remains fascinated by the seemingly perfected processes and intricate designs in nature. Especially in the last few decades, biomimetic, bio-inspired or bio-based systems are being reported extensively in scientific literature, from the fields of sensing, optics to smart coatings and hydrocarbon fuel generation. And why not use nature’s expertise in the field of heat transport and conversion as well? That is exactly what researchers from the Zhejiang A & F University did, as they developed a mini steam generator with the use of bamboo and a widely accessible renewable source: solar energy [1].Steam is a commonly used component in industrial processes, and is typically fueled by (fossil fuel) gasses or electrical power. Photothermal conversion, on the other hand, is the process of converting light or photonic energy to heat.

As solar energy is needed for the heating process, it makes for a rather sustainable technique and a ‘greener’ alternative to most existing steam generators. In light of this upcoming process, Zhang and colleagues designed a novel steam generator that absorbs its light through polypyrrole (PPy), [1] a well-known conducting polymer. The novelty of the steam generator is in the use of bamboo, which is – with its porous and hydrophilic nature – extremely suited as carrier material of PPy and for the transport of fluidic and gaseous water and steam, respectively. As promising efficiencies and evaporation rates were reached, the quest for a scale-up prototype has started, which can eventually and potentially be used best in the seawater desalination and sewage treatment sectors [1].