Dynamic Complex Emulsions as Amplifiers for On-Chip Photonic Cavity-Enhanced Resonators

Suchol Savagatrup, Danhao Ma, Huikai Zhong, Kent S. Harvey, Lionel C. Kimerling, Anuradha M. Agarwal, Timothy M. Swager

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Despite the recent emergence of microcavity resonators as label-free biological and chemical sensors, practical applications still require simple and robust methods to impart chemical selectivity and reduce the cost of fabrication. We introduce the use of hydrocarbon-in-fluorocarbon-in-water (HC/FC/W) double emulsions as a liquid top cladding that expands the versatility of optical resonators as chemical sensors. The all-liquid complex emulsions are tunable droplets that undergo dynamic and reversible morphological transformations in response to a change in the chemical environment (e.g., exposure to targeted analytes). This chemical-morphological coupling drastically modifies the effective refractive index, allowing the complex emulsions to act as a chemical transducer and signal amplifier. We detect this large change in the refractive index by tracking the shift of the enveloped resonant spectrum of a silicon nitride (Si3N4) racetrack resonator-based sensor, which correlates well with a change in the morphology of the complex droplets. This combination of soft materials (dynamic complex emulsions) and hard materials (on-chip resonators) provides a unique platform for liquid-phase, real-time, and continuous detection of chemicals and biomolecules for miniaturized and remote, environmental, medical, and wearable sensing applications.

Original languageEnglish (US)
Pages (from-to)1996-2002
Number of pages7
JournalACS Sensors
Issue number7
StatePublished - Jul 24 2020
Externally publishedYes


  • SiN photonics
  • chemical sensor
  • complex emulsions
  • photonic sensor
  • ring resonator cavity

ASJC Scopus subject areas

  • Bioengineering
  • Instrumentation
  • Process Chemistry and Technology
  • Fluid Flow and Transfer Processes


Dive into the research topics of 'Dynamic Complex Emulsions as Amplifiers for On-Chip Photonic Cavity-Enhanced Resonators'. Together they form a unique fingerprint.

Cite this