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Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2021-12-01 The student, Yi Pei, accepted the attached license on 2019-12-03 at 17:05. The student, Yi Pei, submitted this Dissertation for approval on 2019-12-03 at 17:45. This Dissertation was approved for publication on 2019-12-04 at 17:39. DSpace SAF Submission Ingestion Package generated from Vireo submission #14679 on 2020-02-28 at 17:23:09 Made available in DSpace on 2020-03-02T22:15:06Z (GMT). No. of bitstreams: 2 PEI-DISSERTATION-2019.pdf: 14209320 bytes, checksum: 544495802af7185d43e66f2dfbb1d180 (MD5) LICENSE.txt: 4203 bytes, checksum: 39f4421c94f7ac38b9d77e392cbf17b6 (MD5) Previous issue date: 2019-12-04 Kilian, Kristopher Kilian, Kristopher Braun, Paul Leal, Cecilia Chen, Qian Pei, Yi 2020-03-02T22:15:06Z 2020-03-02T22:15:06Z 2022-03-03T10:15:30Z 2019-12-04 2019-12 Photonic crystal based biosensors are of great interest to researchers because they provide a label-free non-invasive readout, and materials selection can afford biocompatibility towards implantable sensors. The aim of my work is to utilize photonic crystal based biosensors as components of tissue engineering scaffolds to direct cell fate while providing in situ feedback of cell behavior. Porous silicon can be electrochemically etched in ethanolic hydrofluoric acid to produce a range of materials with photonic bandgaps. Different porous silicon photonics including distributed Bragg reflector, rugate filter, microcavity structure and Fano resonance have been explored in my studies. Next, a patterning method has been developed to integrate porous silicon Bragg stacks into a two-dimensional cell culture substrate and the biosensing ability of the Bragg stacks verified through monitoring secretion from live cells in tissue culture. Furthermore, multiple porous silicon rugate filters have been integrated into a three-dimensional tissue-engineering scaffold by using transfer-printing method for in situ enzymatic activity monitoring and therapeutic molecule delivery. To explore other architectures for biosensing, a hydrogel based biosensor has been fabricated by filling biocompatible inverse opal hydrogel with enzyme degradable polymers. Instead of utilizing the swelling of inverse opal backbone, the biosensor takes advantage of the average refractive index change before and after the enzymatic degradation of the infiltrated polymer. Both thin film silicon-based photonic materials and 3D hydrogel photonic materials are biocompatible and can be tuned to display photonic band gap in the near infrared, thereby presenting great opportunities to be used for future tissue engineering applications. Embargo set by: Seth Robbins for item 113909 Lift date: 2022-03-02T22:15:21Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 113909 Lift date: 2022-03-02T22:18:25Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system U of I Only Restriction Lifted for Item 113909 on 2022-03-03T10:15:30Z. application/pdf http://hdl.handle.net/2142/106367 en Copyright 2019 Yi Pei Photonic Crystal Tissue Engineering Photonic crystal biosensors for tissue engineering text text Materials Science & Engineerng Materials Science & Engr University of Illinois at Urbana-Champaign Dissertation Ph.D.