Graduation Year


Document Type




Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Chemical Engineering

Major Professor

Venkat Bhethanabotla, Ph.D.

Co-Major Professor

Thomas M. Weller, Ph.D.

Committee Member

Robert Frisina, Ph.D.

Committee Member

John Kuhn, Ph.D.

Committee Member

Zhimin Shi, Ph.D.


Optical Fiber Interconnects,, 3D Printing, Biosensing, Optoelectronics


Optoelectronics focuses on the application of electronic devices that utilize forms of electromagnetic radiation including visible light and other wavelengths including ultraviolet and infrared. Optoelectronics typically include devices that emit light and detect light. Devices created using this technology include light-emitting diodes, laser diodes, photoresistors, photodiodes, solar cells, phototransistors, and fiber optics. Fiber optic interconnects are interesting devices in that they are used in conjunction with optoelectronic devices to transmit information between individual optoelectronic components.

Optoelectronics are typically produced by traditional lithography methods including etching, writing, and printing on rigid silicon substrates for fabricating devices. Other techniques like glass or plastic extrusion are used to create devices like optical fibers. And finally, non-contact and contact printing of flexible optoelectronics are produced using gravure printing, inkjet printing, and other techniques. These processes are rigid and require masks for lithography or dies for extrusion, or engraved cylinders for gravure printing. So, new designs require tooling and design changes require more tooling. These processes are also planar where structures are built on top of one another on the plane of the substrate and getting the light out of the plane of the substrate requires mirrors or gratings or other complex structures that introduce losses into the designs.

Additive manufacturing is a versatile fabrication method for manufacturing products where layers of liquids, plastic, or metals are deposited on a substrate to create a finished product. Additive manufacturing technology has the potential to economically deliver a large number of products with very little waste in the manufacturing cycle and a low amount of tooling cost other than the capital cost of the additive manufacturing equipment. However, additive manufacturing techniques have not been used outside of research and development to produce optoelectronic devices.

Shape deposition manufacturing (SDM) is hybrid additive and subtractive manufacturing processes where multiple additive and subtractive stages are integrated into the same manufacturing equipment. The particular SDM process used in this work is called laser-enhanced direct print additive manufacturing (LE-DPAM). The use of LE-DPAM to produce optoelectronic devices is a novel method of manufacturing these devices. A detailed description of the techniques, its versatility, and the resolution that can be attained. LE-DPAM technique are applied to the production of optical fiber interconnects and devices based on optical fiber interconnects.

Smooth round optical fiber interconnects are produced on rigid substrates. Smooth surfaces are important and the dynamics within the additive manufacturing liquefier are studied to understand how to optimize surface roughness and therefore optical performance. Limitations and opportunities to improve liquefier design are also investigated that could lead to single mode fiber production. Optical fiber interconnects were also made on flexible substrates where the optical properties were characterized at different flexible conditions along with numerical simulation of optical properties, warp, and strain. And finally, a functional surrounding refractive index sensor is fabricated on a flexible substrate and its performance is characterized.