(4np) Modeling the Physics of Soft and Active Matter for Biological Technologies

Small particles and droplets (both active and passive) at the micrometer and nanometer scales are ubiquitous in many fields, including biotechnology, materials science, and manufacturing. These particles play a critical role in applications such as microfiltration, suspension and emulsion stability, drug delivery, and cell motility. To develop new technologies in these areas, it is essential to have a thorough understanding of the fundamental physics involved in the motion of particles and droplets in fluids.

My research focuses on modeling and analyzing the motion of particles and droplets in low-Reynolds-number flows, which are common in many of these applications. Motivated by both fundamental problems and industrial applications, I develop numerical algorithms for physical simulations of complex systems with high accuracy and efficiency. By using a combination of analytical and numerical tools, my goal is to gain insight into the underlying physical mechanisms of such systems to optimize the design of new technologies. The research in my research group will focus in two main directions: (i) suspension and emulsion dynamics and (ii) soft-particle and droplet microfluidics. Some specific projects are:

1. Dynamics and control of active particles in soft confinements
2. Multiscale simulations of biological systems
3. Microfluidic-based manufacturing of complex-shaped hydrogel particles for drug delivery
4. Hybrid simulations of gel particles in confined environments
   
   

Prior and Current Work

During my PhD, my research focused on two different problems: (a) Modeling the process of mineral recovery using swelling emulsion binders and (b) shape control and active chaotic mixing inside droplets in microfluidic devices. For project (a), I modeled the kinetics of particle agglomeration by swelling double emulsions by investigating how droplet permeability combined with its swelling motion substantially enhances particle capture. This work includes the analysis of the mobility dynamics of pairwise interactions between particles and droplets, an extension of classical collision theory to time-dependent systems of particles with mobile interfaces, and modeling of the swelling of droplets and droplet agglomerates. For the latter, we developed two different approaches: a diffusion-expansion approach and a permeability network model. For project (b), I developed a boundary-integral framework to simulate the motion of deformable droplets inside complex-shaped, three-dimensional microchannels. I used this algorithm to investigate shape manipulation and active mixing inside droplets in a hydrodynamic trap. This work extended recent applications of hydrodynamic traps for the study of extensional rheology to applications such as microchemical reactors and manufacturing of anisotropic soft particles via photopolymerization.

Currently, I am working as a postdoctoral researcher at University of Missouri, where we are developing numerical simulations to study the behavior of macromolecules inside living cells to understand the effects of colloidal-scale mechanics in processes such as RNA translation and DNA transcription, which are essential to life. More specifically, I am building a coarse-grained, confined bead-spring polymer model to study the influence of certain proteins in the chromosome configuration inside a living cell. This problem involves the coupling of numerical simulations over multiple size scales (e.g., atomic, molecular, hydrodynamic), as the coarse-grained forces used in the beads model need to be determined from fine-grain simulations (e.g., all-atom molecular dynamics or Martini fields). Another key part of this project is the collaboration with experimentalists from different institutions to validate our theories.

Teaching Interests

Throughout the years, I had several teaching experiences in different countries. Regarding higher-education teaching, my first significant teaching experience was the opportunity to teach full college-level courses after obtaining my Masters degree in Brazil, where I obtained a lecturer position at the University of Brasilia and taught undergraduate courses in advanced fluid mechanics and thermodynamics/statistical mechanics. During this time, I acquired experience in preparing and giving lectures, as well as preparing homework sets and exams. In the United States, during my PhD, I served as a TA for graduate-level courses on mathematical methods and microhydrodynamics, for which I hosted office hours and helped preparing homework sets and a few exam problems — I also prepared and gave a few lectures for each course.

I also had the chance to mentor several (eight in total) undergraduate students on their research through programs such as the Summer Program for Undergraduate Research (SPUR) and Discovery Learning Apprenticeship (DLA), which were designed to introduce undergraduate students to research. For three of these undergraduate students, I also served as a graduate mentor for their senior theses at the University of Colorado Boulder. I also tutored multiple undergraduate students for classes in heat and mass transfer and fluid mechanics through the Graduate Assistance in Areas of National Need (GAANN) program in our department.

Regarding my personal teaching interests, although I am fully prepared to teach any of the chemical and mechanical engineering core courses, I am most interested in teaching courses such as Fluid Mechanics, Heat and Mass Transfer, Thermodynamics, System Dynamics and Control, and Mathematical/Numerical Methods in Engineering, as these are strongly related to my background and research. I would also like to teach graduate-level courses on Advanced Fluid Mechanics, Microhydrodynamics, Soft Matter, and Advanced Mathematical/Numerical Methods.