3D LED Printer Makes a Contact Lens Display Possible

3D Printed Contact Lenses 

According to researchers, 3D printed contact lenses can now be used like Google Glass or head up display showing the wearers’ data as well as monitor their health. 3D printer build up metallic or polymer material to form objects when instructed by computer code that conveys to the machine the desired dimension together with the appearance of the product, though this machine is more complex.

Researchers have started constructing prototypes for contact lens displays, and their biggest impediment was parts of fabrication which on a theoretical level is not difficult to build display in a contact lens but building and placing the tiny interrelated parts on a tiny polymer disk is a difficult task.

The 3D LED printer is a 3D quantum dot LED printer which on breaking the concept of an LED to its most basic form, researchers envisaged that they need not think of LEDs like small plastic light bulbs but stacks of interacting substance.

The printer on its part could lay down an LED with a sandwich type of a structure which is not unlike a single pixel in a display of OLED and get emissive layer which is nanoparticles of cadmium selenide that is referred to as quantum dots.

Active Approach

The quantum dots or nano sized crystals of certain substance exhibit unique or particular useful electronic properties. These are sandwiched between one layer which can donate electrons and one layer that accepts them and the entire process can be fused to a surface due to the bottom adhesive layer that is activated with the help of UV light.

Moreover, the printed LEDs are ultra-thin, almost transparent as well as flexible. The transfer of electrons through quantum dot layer causes the dots to produce photons of light and the main advantage of it is that they can be made to emit light at very specific wavelength or colours.

It means that the quantum dot screens can display more recreations of colour accurately but it would not be the first priority for contact lens display which will get static, sensible image in the user’s eye.The pixel on the other hand in a contact lens display could take one of two forms and the active approach uses individual pixel as a light source and emits photons in the eye, creating an image directly.

Passive Approach 

The passive approach on the other hand uses less power though it would be more difficult using individual pixel to bend the incoming light from the environment to portray a new picture on the retina. The issue with active approach is that it needs a good amount of power to go on and wireless power collection relies partially on physical size of the collecting antenna.

When the antenna must be physically fitted in a contact lens, it creates a hard upper limit on power supply. It is unlikely to start printing smartphone screens pixel by pixel since manufacturing in bulk would be quicker and cheaper and while doing so, things like putting LEDs in circular area of contact lens less than 2 mm, it could be helpful. The cost of the prototype print cost about $20,000 to create though there is a possibility in reduction of cost in the near future.