3D Conductive monolithic carbons from pyrolyzed bamboo for microfluidic self-heating system

Bamboo, like wood, is a promising natural template for biobased devices that takes advantage of its hierarchical architecture, microarray channels, mechanical and electrical anisotropic properties.1-4 A novel conductive three-dimensional carbonaceous material (3D-CM) was obtained with a low-heat thermal treatment (HTT) at 700ºC. Highly oriented crystalline cellulose structure of bamboo and its microarray channels with resistive behavior (ρ, 0.15 Ω m, and σ, 6.6 S/m) were used as continuous 3D microfluidic heaters exploring a Joule effect when is applied a direct current to the 3D-CM. By small manipulations of the applied electric current, we were able to obtain a fine control of the fluids' output temperature passing through the conductive carbon micro-channel arrays. The monolithic 3D-CM was used as a 3D microfluidic self-heating system to heat polar solvents (H2O and ethylene glycol) in flow mode up to their boiling points. A 2D carbon hotplate heater was built-up to warm solvent in batch mode. A complete chemical and physical characterization of the chemical and physical evolution will be presented to determine the structural and chemical compositions, cellulose crystalline structure phase transition to graphitic/turbostratic carbon, thermal conductivity of unprecedented bambootronics bio-devices. The microfluidic self-heating system could be implemented for new chemical platforms with a fine-tuning of the reaction temperatures in flow chemistry. The sustainable and low-cost prototyping of our bambootronics systems could pave the way for new eco-friendly carbonaceous-based devices with a high impact on the circular economy.