📝 Publications

Active Transport as a Mechanism of Microphase Selection in Biomolecular Condensates
Le Qiao, Peter Gispert, Lukas S. Stelzl, Friederike Schmid. (2026). Phys. Rev. Research, accepted.

• Using a minimal diffusion-transport model together with linear stability theory and three-dimensional simulations, we show that motor-driven active transport along cytoskeletal networks can arrest the coarsening of biomolecular condensates, selecting a finite droplet size tunable from hundreds of nanometers to microns. This mechanism also drives shape transitions from spherical to cylindrical condensates, pointing to a route for engineering programmable active emulsions.

Stability and Elasticity of Ultrathin Sphere-Patterned Block Copolymer Films
Le Qiao, Daniel A. Vega, Friederike Schmid. (2024). Macromolecules. 57(9) 4629-4634.

• We use self-consistent field theory (SCFT) to investigate the elastic response of sphere monolayer films with respect to in-plane shear, in-plane extension, compression deformations, and bending. We demonstrate that the bending constants are found to be negative, indicating that free-standing block copolymer membranes made of only a sphere monolayer are inherently unstable above the glass transition.

Particle-Mediated Tuning of Defect Stability in Lamellar Block Copolymer Systems
Le Qiao, Daniel A. Vega, Friederike Schmid. (2026). arXiv:2608.30981.

• Using a hybrid particle/Ginzburg–Landau model with finite-size scaling, we study how colloidal particles change the formation energy of dislocation defects in lamellar block copolymers. Homogeneous particles increasingly stabilize dislocations as their size grows, while balanced Janus particles instead raise the formation energy, offering design rules for controlling defects in particle-doped films.

Ratcheting Charged Polymers through Symmetric Nanopores Using Pulsed Fields: Designing a Low Pass Filter for Concentrating Polyelectrolytes
Le Qiao, Kai Szuttor, Christian Holm, Gary W. Slater. (2023). Nano Letters. 23(4) 1343-1349.

• We present a new concept for the separation of DNA molecules by contour length that combines a nanofluidic ratchet, nanopore translocation, and pulsed fields. Using Langevin dynamics simulations, we show that it is possible to design pulsed field sequences to ratchet captured semiflexible molecules in such a way that only short chains successfully translocate, effectively transforming the nanopore process into a low pass molecular filter.

Capture and Translocation of a Rod-Like Molecule by a Nanopore: Orientation, Charge Distribution and Hydrodynamics
Le Qiao, Gary W. Slater. (2022). Phys. Chem. Chem. Phys.. 24, 6444-6452.

• Using hybrid Langevin dynamics and lattice Boltzmann simulations with P³M electrostatics, we study how the charge distribution along a rod-like molecule shapes its capture and translocation through a nanopore. Rod orientation evolves asymmetrically between capture and escape despite symmetric field lines, and rods launched near the wall are captured faster because they align with the local field — while the orientational capture radius we proposed earlier remains valid once electrohydrodynamic interactions are included.