Investigating electron (hole) transfer in conductive polymers and charge structure coupling in conductive soft matter. The long-term goal is to design charge-structure coupling for efficient soft electronics devices and memristors for neuromorphic computing, and intelligent soft materials (artificial brain) that can efficiently process information.
We investigate these systems by employing Monte Carlo and molecular dynamics simulations, combined with new algorithm development for charge transfer within classical MD simulations. Moreover, we develop methods that incorporate hydrodynamic interactions with coarse-grained models of charged molecules and soft materials.

Discontinuous Transition in Electrolyte Flow through Charge-Patterned Nanochannels
T Curk*, S. G. Leyva, I. Pagonabarraga
Phys. Rev. Lett. 133 (2024) [pdf]

Lipid nanoparticle self-assembly and growth. We strive to understand the kinetics of RNA-lipid nanoparticle self-assembly, how to kinetically control the particle size and minimize polydispersity. We mainly employ analytical kinetic theory, kinetic Monte Carlo and molecular dynamics simulations. Ongoing collaboration with the group of Hai-Quan Mao.

Single-Particle Spectroscopic Chromatography Reveals Heterogeneous RNA Loading and Size Correlations in Lipid Nanoparticles
S. Li, Y. Hu*, J. Lin, Z. Schneiderman, F. Shao, L. Wei, A. Li, K. Hsieh, E. Kokkoli, T. Curk*, H.-Q. Mao*, T.-H. Wang*
ACS Nano 2024, 18, 24, 15729–15743 [pdf]

Many medical conditions can be detected or diagnosed by analyzing chemical compounds circulating in the bloodstream or that are in other body liquids.To confidently detect these proteins quickly and easily, electronic sensors are needed that signal when they are in contact with the proteins that indicate the medical condition of interest to a patient. One way to improve the certainty that a sensor signal is indicating the presence of a particular protein is to provide circuits that remove signals that come from other compounds in the liquids being analyzed, like salt, fats, and additional proteins. This project investigates a new circuit, constructed with new biologically-derived electronic materials, designed to remove these unwanted signals that make it more difficult to detect the proteins that indicate medical conditions. In collaboration with Howard Katz and Supported by NSF CBET award No. 2402407.

A Study of the Drift Phenomena of Gate-Functionalized Biosensors and Dual-Gate-Functionalized Biosensors in Human Serum
Y. Song, N. Chen, T. Curk*, H. E. Katz*, Molecules 29 (7), 1459 (2024)

We are investigaing charge-structure coupling in nanoparticles and polyelectrolytes for designing e.g. nano-actuators for soft robotics. Nanoparticles, polyelectrolytes and biomolecules in solution acquire charge through the dissociation or association of surface groups. Thus, a proper description of their electrostatic interactions requires sampling of protonation states and the use of charge-regulating boundary conditions rather than the commonly employed constant-charge approximation. We provide an open-source implementation of the charge-regulation solver for the LAMMPS molecular dynamics package.

Collapse and expansion kinetics of a single polyelectrolyte chain with hydrodynamic interactions, J. Yuan and T. Curk, J. Chem. Phys. 160, 161103 (2024)

Dissipative particle dynamics for coarse-grained models , T. Curk, J. Chem. Phys. 160, 174115 (2024)

Charge-regulation effects in nanoparticle self-assembly, T. Curk and E. Luijten, Phys. Rev. Lett. 126, 38003 (2021) [Editor’s Suggestion]

Accelerated simulation method for charge regulation effects T. Curk, J. Yuan and E. Luijten, J. Chem. Phys. 156 (2022)