Printed Optics and Electronics
November 20, 2013, Printed Electronics Show, Santa Clara, CA—Karl Willis from Autodesk talked about creating new forms of displays and combining optics and electronics with 3-D printers. The goal is customized objects from fully printed devices.
In collaboration with Disney, they developed new form factors for displays, sensors, and illumination. Light pipes inside a 3-D object enables mobile projectors and table-top displays. Placing air pockets within the object causes internal reflections for a volumetric display. These internal displays can be of any geometry.
Sensors are created by incorporating mechanical and optical functions. For example, a light guide on a cantilever can be a switch. A flexible beam can function as a slider control or, if in a circular pattern, as a rotary dial. The amount of light will vary with displacement of the free end, so distance from the hinge point results in more deflection and less light to the sensor. The beam could also operate as a simple accelerometer.
A touch on a surface changes the index of refraction, enabling touch sensors with no wiring. The changes in internal reflection will redirect the light away from the sensor indicating a touch. This changing reflection is not very high resolution, but is sufficient for simple, multiple-button controls.
Illumination takes advantage of the materials properties to make lenses, prisms, and reflectors. The combination of optical functions and 3-D printing allows for the creation of light bulbs of any arbitrary shape. The resulting chandelier would have the light bulbs as a visible part of the structure, rather that having to obscure the bulbs with other optical pieces.
The main limits for optical functions is the printer resolution. For most materials, the light loss is much higher than through optical fiber, and the surfaces need a lot of polishing to make a reasonable optical surface. A Frenel lens is no problem due to the stepped nature of this type of lens, but most functions need a smooth surface for the optical functions to be controllable.
Printed electronics can be a big part of the whole system. The creation of a series of techniques for printing the optical devices can be merged with electrical and optical components to enable new devices.
