The innovation engine for new materials

Marielle Cooper

Marielle Cooper


CCS Chemistry


University of California, Santa Barbara


Ke-Chu Lee

Faculty Sponsor(s): 

Paolo Luzzatto-Fegiz

Faculty Sponsor's Department(s): 

Mechanical Engineering

Project Title: 

Computer Controlled Manipulation of Multi-Phase Flow Using Light Responsive Surfactants

Project Description: 

Photosurfactants offer the ability to vary interfacial tension of fluids on demand, allowing manipulation of multi-phase flow. Dynamic ability to control multi-phase flow offers the capacity to improve phase change heat transfer (evaporation, condensation, boiling) valuable, for example, in power plants or heating and cooling applications. Current methods of photosurfactant control are limited to an individual manually manipulating a single droplet via a laser; this research seeks to design a computer-controlled mechanism to manipulate the photosurfactant, in order to enable precise comparison to theory, as well as high-throughput manipulation. We chose spiropyran as the photosurfactant, due to its ease of activation. The optimal wavelength absorbance of spiropyran is 365 nm, requiring a non-commercially available UV light matrix. To test the spiropyran we built a UV 8x8 matrix capable of being suspended above or below a petri dish containing the photosurfactant mixture. An Arduino Uno was used to control the matrix, allowing the design and implementation of various simple light patterns on the LED matrix. A computer control mechanism to manipulate the photosurfactant expands the application of photosurfactants by expanding control over photosurfactant movement. The experimental design introduced here will allow for further testing and refinement of multi-phase flow manipulation. Future work involves applying these LED patterns to move a single spiropyran droplet and determine the necessary exposure time to move the droplet between LEDs. Upon successful control of a single droplet, the project will move to control multiple droplets as well as determine parameters such as the intensity and length of exposure required to combine two droplets.