The limitation of projection microstereolithography in additive manufacturing methods is that they typically use a single-aperture imaging configuration, which restricts their ability to produce microstructures in large volumes owing to the trade-off between image resolution and image field area. Here, we propose an integral lithography based on integral image reconstruction coupled with a planar lens array. The individual microlenses maintain a high numerical aperture and are used to create digital light patterns that can expand the printable area by the number of microlenses (10 3 to 10 4 ), thereby allowing for the scalable stereolithographic fabrication of 3D features that surpass the resolution-to-area scaling limit. We extend the capability of integral lithography for programmable printing of deterministic nonperiodic structures through the rotational overlapping or stacking of multiple exposures with controlled angular offsets. This printing platform provides new possibilities for producing periodic and aperiodic microarchitectures spanning four orders of magnitude from micrometers to centimeters.

Additive manufacturing techniques are used to fabricate functional microstructures with customised mechanical and chemical properties. One common technique is projection microstereolithography, which has recently been developed to support smaller features, larger build areas, and/or faster speeds. The limitation of such systems is that they typically utilise a single-aperture imaging configuration, which restricts their ability to produce microstructures in large volumes owing to the tradeoff between image resolution and image field area. In this paper, we propose an integral lithography technique based on integral image reconstruction coupled with a planar lens array. The individual microlenses in the planar lens array maintain a high numerical aperture and are employed to create digital light patterns that can expand the printable area by the number of microlenses (10^3-10^4). The proposed lens array-based integral imaging system can simultaneously scale up and scale down incoming image fields, thereby allowing for the scalable stereolithographic fabrication of three-dimensional features that surpass the resolution-to-area scaling limit. We extend the printing capability of integral lithography to fabricate deterministic nonperiodic structures through the rotational overlapping or stacking of multiple exposures with controlled angular offsets. The proposed system provides new possibilities for producing periodic and deterministic aperiodic microarchitectures spanning four orders of magnitude from micrometres to centimetres. These microarchitectures can be applied to biological scaffolds, chemical reactors, functional surfaces, and metastructures.

No abstract