Ceramic ultra-thin coatings using atomic layer deposition

Ultra-thin films can be coated on primary fine particles without significant aggregation by atomic layer deposition (ALD) in a fluidized bed reactor. Precursor doses can be delivered to the bed of particles sequentially and, in most cases, can be utilized at nearly 100% efficiency without precursor breakthrough and loss, with the assistance of an inline downstream mass spectrometer. A multitude of applications can be addressed in a competitive fashion using fine particles that have been surface-modified using ALD in scalable, high-throughput unit operations. Several examples of the applications of conformal ALD coatings have been discussed, including oxidation-resistant metals or ceramics, coatings that enable biomedical applications including tissue engineering, and corrosion-resistant particles for next-generation batteries, capacitors or fuel cells. It is expected that the technology of thin film coating by particle ALD will play a major role in the field of advanced materials.