A new method was developed to make a low-cost, high-quality lens quickly using a 3D printer. The technology could be used to create optical imaging lenses, customized contact lenses for correcting distorted vision, or to turn iPhones into microscopes for disease diagnosis.
The customized optical component is 5 millimeters in height and 5 millimeters in diameter, and can be 3D-printed in about four hours. Creating the lenses involves placing layer upon layer of material. When the lens was first printed, its curved layers, made of a photo-curable resin, created a visible stepping, or roughness. The layer thickness is typically 5 microns, while the wavelength of visible light is around 0.5 micron. This creates an optically rough surface, which made the lens incapable of clear optics.
A two-step process of layering and polishing was developed. First, grayscale images were used to create more transitions between steps. Then, the surface was coated with the same photo-curable resin, forming the meniscus that further smooths the surface. This resulted in a transparent lens with a smooth surface.
This process could lead to a plethora of new devices with a wide variety of applications in optics and biomedical imaging. Future work will involve making larger lenses as well as investigating how to integrate the 3D-printed lens with medical devices such as an endoscope or optical microscope. The lenses could be used by doctors in underdeveloped areas for diagnostic imaging, or by field scientists as portable microscopes. The lens could also be fashioned into a customized contact lens for people with distorted corneas caused by keratoconus.