Batteries that make themselves could serve as tiny power sources in micromachines or microelectronics
Source: “Self-Assembling Colloidal-Scale Devices: Selecting and Using Short-Range Surface Forces between Conductive Solids”
Yet-Ming Chiang et al.
Advanced Functional Materials 17(3): 379-389
Results: Thanks to a better understanding of short-range forces between microscopic particles, MIT researchers were able to identify materials that, combined in a solution, will arrange themselves to form a working rechargeable battery. In a prototype, attractive forces cause microscopic carbon particles to aggregate, forming an electrode and attaching to a current collector. Another, preëxisting electrode–a solid slab–repulses the particles, creating the necessary gap between electrodes.
Why it matters: Such materials could self-assemble into form-fitting batteries in electronic devices. The materials could also be used in tiny sensors or micromachines.
Methods: The researchers combined theoretical analysis with precise measurements of the short-range attractive and repulsive forces between particles of different materials. The measurements were made by attaching particles to the tip of an atomic force microscope. The interplay of forces caused the researchers’ chosen materials to sort themselves into a working battery.
Next Steps: To make the battery more rugged, the researchers want to replace the liquid electrolyte used in the prototype with a polymer. Also, future prototypes could use self-assembling particles for both electrodes, not just one.