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Sensing and Actuation from Biology to Electronics


Pai, Alex Hao-Yu (2015) Sensing and Actuation from Biology to Electronics. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z9NC5Z5M.


We introduce an in vitro diagnostic magnetic biosensing platform for immunoassay and nucleic acid detection. The platform has key characteristics for a point-of-use (POU) diagnostic: portability, low-power consumption, low cost, and multiplexing capability. As a demonstration of capabilities, we use this platform for the room temperature, amplification-free detection of a 31 bp DNA oligomer and interferon-gamma (a protein relevant for tuberculosis diagnosis). Reliable assay measurements down to 100 pM for the DNA and 1 pM for the protein are demonstrated. We introduce a novel "magnetic freezing" technique for baseline measurement elimination and to enable spatial multiplexing. We have created a general protocol for adapting integrated circuit (IC) sensors to any of hundreds of commercially available immunoassay kits and custom designed DNA sequences.

We also introduce a method for immunotherapy treatment of malignant gliomas. We utilize leukocytes internalized with immunostimulatory nanoparticle-oligonucleotide conjugates to localize and retain immune cells near the tumor site. As a proof-of-principle, we develop a novel cell imaging and incubation chamber for in vitro magnetic motility experiments. We use the apparatus to demonstrate the controlled movement of magnetically loaded THP-1 leukocytes.

Finally, we introduce an IC transmitter and power ampli er (PA) that utilizes electronic digital infrastructure, sensors, and actuators to self-heal and adapt to process, dynamic, and environmental variation. Traditional IC design has achieved incredible degrees of reliability by ensuring that billions of transistors on a single IC die are all simultaneously functional. Reliability becomes increasingly difficult as the size of a transistor shrinks. Self-healing can mitigate these variations.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:sensing actuation biosensing glioma self-healing trafficking
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Minor Option:Biochemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Hajimiri, Ali
Thesis Committee:
  • Hajimiri, Ali (chair)
  • Yang, Changhuei
  • Rutledge, David B.
  • Weinreb, Sander
  • Choo, Hyuck
Defense Date:29 May 2015
Funding AgencyGrant Number
Caltech Innovation Initiative (CI2) Research Grant.UNSPECIFIED
City of Hope National Cancer InstituteCancer Center Support Grant
Record Number:CaltechTHESIS:05302015-005943888
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:8944
Deposited By: Alex Pai
Deposited On:05 Jun 2015 18:03
Last Modified:04 Oct 2019 00:08

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