Search for: All records

We report a simple approach to develop transient microbial fuel cells with the capability of dissolving in water after stable power generation within a programmed period. This novel watersoluble biobattery makes use of the integration of a dissolvable paper-based substrate, a simple pencil-drawn graphite anode, and a Prussian-blue (PB) cathode. The device features (i) a low cost transient paper-based platform, (ii) easily accessible electrode materials and simple fabrication steps and (iii) a time-controlled operation by using the number of serpentine microfluidic channels. The biobatteries reached to a maximum power of 0.5μW and a current 15.6μA 

We report a simple approach to develop transient microbial fuel cells with the capability of dissolving in water after stable power generation within a programmed period. This novel water-soluble biobattery makes use of the integration of a dissolvable paper-based substrate, a simple pencil-drawn graphite anode, and a Prussian-blue (PB) cathode. The device features (i) a low cost transient paper-based platform, (ii) easily accessible electrode materials and simple fabrication steps and (iii) a time-controlled operation by using the number of serpentine microfluidic channels. The biobatteries reached to a maximum power of 0.5μW and a current 15.6μA and achieved full dissolution in less than 60 minutes. 

We demonstrate a self-folding paper robot with capillary force driven fluid. When water is sprayed on fluidic channels patterned on paper, the 2-D sheet of paper can be controllably self-folded into various 3-D structures; half-oval, circle, round-edge square, triangle, half-circle, and table. The self-folding paper sheet can be readily fabricated via a double-sided wax printing method, forming a bilayer structure of the fluidic channel and the hydrophobic wax, in which these two layers have different swelling/shrinking properties. The patterned paper performs folding actuation with water and unfolding behavior with evaporation without being mechanically manipulated by external forces or moments. Finally, we create a paper gripper based on this self-folding actuation, conveying a low-weight object. This report demonstrates the possibility of paper microfluidics for self-folding actuation and soft robotics. 

In this work, we report a papertronic sensing system with the ability to achieve easy, rapid, and sensitive characterization of bacterial electrogenicity from a single drop of culture. Paper was used as a device substrate that inherently produces favorable conditions for easy, rapid, and sensitive and potentially high-throughput controlling of a microbial liquid sample. Through an innovative microscale device structure and a simple transistor amplifier circuit directly integrated into a single sheet of paper substrate, a powerful sensing array was constructed, resulting in the rapid and sensitive characterization of bacterial electrogenicity from a microliter sample volume. The microbial current generations were amplified by the transistor providing power to a 4-wide LED circuit board indicator bar for the direct visual readout with the naked eyes. Depending on bacterial electrogenicity, the LED intensity was changed. We validated the effectiveness of the sensor using two known bacterial electrogens (wild-type S. oneidensis and P. aeruginosa) and hypothesis-driven genetically modified P. aeruginosa mutant strains.