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Real-Time Biosensing and Energy Harvesting on Human Body


Cho, Hyunjun (2020) Real-Time Biosensing and Energy Harvesting on Human Body. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/ZN7F-ZF71.


This thesis covers two technologies that can be applied to the human body for real-time applicable usages: biosensors and energy harvesters. The first part of the thesis describes optical biosensing techniques based on surface-enhanced Raman spectroscopy (SERS). Our large-scale spatially uniform Raman enhancing substrates allow low-level bio molecule detection due to their strong plasmonic enhancement of the 3D Au-NP clusters. This method also enables low-level insulin sensing as well as insulin concentration analysis in islet secretion. These results can lead to developing simple and easy biosensing methods allowing real-time biosensing applications including convenient monitoring of health, early disease detection, and diabetes-related clinical measurements.

The second part of the thesis suggests an energy harvesting method using vocal vibrations. The vocal folds produce mechanical vibrations that can serve as an energy source with consistent amplitude and frequency. The vibration hotspots exist at various locations on the human upper body. The energy harvesting system consisting of piezoelectric devices and energy harvesting circuits generates 3.99 mW of electrical power. The amount of energy generated from vocal vibrations is sufficient to charge a Li-Po battery which can drive an LCD display or charge Bluetooth headphones. This method demonstrating a relatively high power generation and convenience of practical use can provide a real-time complementary charging technique for wearable electronics like wireless headphones and smart glasses as well as medical implantable devices such as deep brain stimulators, cochlear implants and pacemakers.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Surface enhanced Raman spectroscopy, label-free insulin sensing, vocal fold vibrations based energy harvesting, implantable energy harvesting devices
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Choo, Hyuck (advisor)
  • Gharib, Morteza (advisor)
Thesis Committee:
  • Vaidyanathan, P. P. (chair)
  • Gharib, Morteza
  • Scherer, Axel
  • Choo, Hyuck
Defense Date:14 June 2019
Non-Caltech Author Email:caohj82 (AT)
Funding AgencyGrant Number
GIST-Caltech Collaborative Research CG2016
Projects:Surface-Enhanced Raman Spectroscopy-Based Label-Free Biosensors, Vocal Vibrations-Driven Energy Harvesters
Record Number:CaltechTHESIS:07252019-145728798
Persistent URL:
Related URLs:
URLURL TypeDescription adapted for Chapter 2. adapted for Chapter 3. adapted for Chapter 4. adapted for Chapter 5.
Cho, Hyunjun0000-0002-8963-5525
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11754
Deposited By: Hyunjun Cho
Deposited On:26 Jul 2019 23:12
Last Modified:26 Oct 2023 20:10

Thesis Files

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