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 hierarchicalarchitecture, microarray channels, anisotropic mechanical and electrical properties. Herein we report a low heatthermal treatment (HTT, 700-1000 oC) of natural bamboo specimens to obtain bamboo-based graphitic deviceswith thermoelectric and electrochemical properties. The preservation of the highly anisotropic architecture ofthree-dimensional carbon material (3D-CM) allowed adding specific thermoelectric and electrochemical propertiesdepending on the HTT of the pristine specimens. High electric conductivity (?, 839 S/m) was observed at1000 oC showing a remarkable potential application as a bamboo-based working electrode. The bambooannealed to 700 oC showed higher resistivity (?, 0.15 ? m, and ?, 6.6 S/m), thermal conductivity (1.77 W/m K),and thermal heating rate (1.0 oC/s). The pyrolyzed biomass (B-700) was used as a 3D microfluidic heater to heatpolar solvents (H2O and ethylene glycol) in flow mode up to their boiling points. A 2D carbon hotplate heaterwas built-up to warm solvent in batch mode. A complete chemical and physical characterization of the samplesallowed us to determine structural and chemical compositions, cellulose crystalline structure phase transition tographitic/turbostratic carbon, thermal and electrical conductivity of unprecedented bambootronics bio-devices.