An atomic layer deposition system for depositing thin layers of material onto a common substrate includes a deposition head shaped to define a conical interior cavity into which a conical deposition drum is disposed. Together, the deposition head and the deposition drum define a narrow gap adapted to receive the common substrate, the spacing of the narrow gap being adjustable through acute axial displacement of the deposition head relative to the deposition drum. A pair of rollers advances the substrate through the gap in a first direction, as the deposition head rotates in the opposite direction at a precise rate. Each of the deposition head and deposition drum includes a plurality of separate fluid channels which enable gasses utilized in the deposition process to be delivered into and exhausted from the narrow gap, with the delivery of inert gas on both sides of the substrate effectively creating an air bearing.