About

Michael Bevan is a professor of chemical and biomolecular engineering at Johns Hopkins University. His research focuses on measuring and manipulating nanoparticle and biomolecular interactions, dynamics, and structures in interfacial and confined systems. The Bevan Lab’s work has direct relevance to traditional complex fluid and soft matter applications such as coatings, ceramics, and consumer products, as well as emerging nanotechnologies involving particle-based materials and devices, including metamaterials, drug delivery systems, antennas, and diagnostics. His approach involves developing an integrated suite of advanced microscopy and computer simulation tools to design, control, and optimize colloidal interactions for use in advanced materials, environmental, and biomedical applications. Professor Bevan received a Bachelor of Science in both Chemical Engineering and Chemistry from Lehigh University in 1994 and earned his PhD from Carnegie Mellon University in 1999. He was named a fellow of the American Chemical Society in 2016.

Research topics

• Computer Science
• Artificial Intelligence
• Composite material
• Control engineering
• Environmental science
• Human–computer interaction
• Physics
• Materials science
• Engineering

Selected publications

• Drug & virus transport across biological barriers: interactions, diffusion, partitioning, permeability, and selectivity

  Soft Matter · 2026-01-01

  articleOpen accessSenior author

  -scale attractive interactions, that are either specific or non-specific, can yield optimal delivery of larger particles, to increase the mass flux across mucus barriers by an order of magnitude, and enable delivery of macromolecular cargo, due to enhanced partitioning. Our model indicates drug particle design rules to achieve transport rates comparable to or exceeding what is possible by viruses with highly evolved chemical and physical characteristics.

  PublisherDOI

• Closed Loop Navigation of a Complex State Space: Assembling Anisotropic Colloids into Perfect Crystals

  ACS Nano · 2026-04-16

  articleSenior authorCorresponding

  Controlling the reliable rapid assembly of different shaped colloidal building blocks into low-defect microstructures is an open challenge that could enable numerous advanced material technologies. Limitations to addressing this problem include scientific challenges with understanding nonequilibrium microstructure evolution and technological challenges with controlling such stochastic dynamic processes. To navigate a complex multistate colloidal assembly process, here we implement closed loop-controlled assembly of rectangular particle monolayers in AC electric fields, which can form over a dozen states including multiple liquid, liquid crystal, crystal, and glassy states. In optical microscopy experiments, we navigate between multiple stable, metastable, and transient states with varying degrees of particle orientational and positional order by implementing kT-scale tunable dipolar potentials, identifying low dimensional reaction coordinates that capture all states and pathways, and designing control policies informed by microstructure evolution on underlying free energy landscapes. The resulting control scheme enables rapid assembly along dynamic pathways on different energy landscapes that circumvent and/or repair orientational defects in nematic states and positional defects in crystal states. Our findings demonstrate a generalizable first-principles approach to control microscopic assembly processes with broad implications to understanding stochastic nonequilibrium self-assembly dynamics and realizing high-value-added microstructured materials.

  PublisherDOI

• Fabrication and Modeling of a Thermoreversible Modular Core–Shell Colloidal System

  Langmuir · 2025-09-24

  articleOpen access

  A widely used model system in rheological studies of colloidal gels consists of octadecyl-coated silica particles that undergo thermoreversible gelation in specific suspending media. Their standard synthesis protocol involves an etherification of octadecanol and suffers from poor reproducibility with varying grafting densities and, therefore, transition temperatures. To overcome this limitation, we present here an alternative approach using an amine-yne click-like reaction to graft octadecyl chains onto the particle surface with high fidelity. Suspended in tetradecane, these particles exhibit a reversible liquid-solid transition below 20 °C─making them ideal for comparative studies, particularly by avoiding complications in the rheological characterization due to loading history or thixotropic effects. By fine-tuning the reaction conditions, we precisely control the grafting density─and thus the gelation. The resulting interparticle interactions can be described as a superposition of temperature-dependent forces: repulsion at high temperatures, van der Waals attraction, and temperature-dependent chain-chain interactions, and their resulting potentials can be validated with AFM measurements. The accurate tuning of interparticle potentials makes this model system ideally suited for quantitative comparisons between experiments and simulations across relevant length scales.

  PublisherDOI

• Dielectrophoretic Polarizability of Surface‐Modified Particles for Studying Induced‐Charge Electroosmotic Flows

  Advanced Functional Materials · 2025-02-28 · 5 citations

  articleOpen access

  Abstract Induced‐charge electroosmosis (ICEO) offers a practical approach to drive microscale flows by application of AC electric fields across polarizable surfaces, enabling diverse functions including microfluidic pumping, active cargo transport, and biosensing. While ICEO along pristine surfaces is well‐understood, practical applications of ICEO often require surface modifications that affect ICEO flows in a manner that is poorly understood. Here, this study introduces dielectrophoretic (DEP) polarizability measurement, DPM, as a method to study effects of surface modifications on surface polarizability and ICEO flows. The method entails DEP trapping of probe particles and analysis of their equilibrium motions to measure polarizability. This DPM‐generated polarizability data is then used to predict effects of surface modifications on ICEO flows and reveal the contribution of additional factors affecting ICEO. It compares predictions with experimentally observed changes to the speed of Janus particles traveling by ICEO‐driven induced‐charge electrophoresis. This study shows that DPM enables prediction of decreased particle speed upon protein capture by functional Janus particles and reveals that increased speed of polymer‐modified Janus particles likely arises from hydrodynamic factors. Overall, this work lays the foundation for investigating new ICEO‐driven systems with applications in complex environments, potentially including those encountered in biosensing, remediation, or cargo delivery.

  PublisherOA PDFDOI

• <i>kT</i>- &amp; <i>fN</i>- Scale Polymer Brush Interactions: Theory vs Experiment for Aqueous Polyethylene Glycol Layers

  Macromolecules · 2025-08-20 · 1 citations

  articleSenior authorCorresponding

  We report direct sensitive measurements of separation dependent energy and force between aqueous polyethylene glycol (PEG) brushes, which are compared to scaling and self-consistent field theories with complete independently characterized polymer solution properties. By nonintrusively measuring and analyzing Brownian collisions between polymer coated colloids and surfaces using total internal reflection microscopy, we directly measure PEG brush interactions in physiological ionic strength aqueous media with nanometer-, kT-, and femtonewton-scale resolution. The measured brush interactions agree with the self-consistent field theory model with no adjustable parameters. By considering small-compression of polymer brushes due to kT-scale free energy changes, a simplified exponential interaction potential between brush coated colloids and surfaces is developed to also accurately capture the direct measurements using the same polymer solution properties. Our findings demonstrate the self-consistent field theory and a simple generalizable potential validated against directly measured PEG brush interactions, which can be used to reliably predict and interpret interactions between polymer brush coated colloidal particles in diverse materials and applications.

  PublisherDOI

• Fabrication and Modeling of a Thermoreversible Modular Core–Shell Colloidal System

  Repository for Publications and Research Data (ETH Zurich) · 2025-10-07

  otherOpen access

  A widely used model system in rheological studies of colloidal gels consists of octadecyl-coated silica particles that undergo thermoreversible gelation in specific suspending media. Their standard synthesis protocol involves an etherification of octadecanol and suffers from poor reproducibility with varying grafting densities and, therefore, transition temperatures. To overcome this limitation, we present here an alternative approach using an amine–yne click-like reaction to graft octadecyl chains onto the particle surface with high fidelity. Suspended in tetradecane, these particles exhibit a reversible liquid–solid transition below 20 °C─making them ideal for comparative studies, particularly by avoiding complications in the rheological characterization due to loading history or thixotropic effects. By fine-tuning the reaction conditions, we precisely control the grafting density─and thus the gelation. The resulting interparticle interactions can be described as a superposition of temperature-dependent forces: repulsion at high temperatures, van der Waals attraction, and temperature-dependent chain–chain interactions, and their resulting potentials can be validated with AFM measurements. The accurate tuning of interparticle potentials makes this model system ideally suited for quantitative comparisons between experiments and simulations across relevant length scales.

  PublisherDOI

• Feedback Controlled Reconfiguration of Ellipsoidal Colloids between Interfacial Liquid, Nematic, and Crystal States

  ACS Applied Materials & Interfaces · 2025-10-22 · 1 citations

  articleSenior authorCorresponding

  We report AC electric field mediated feedback control over the reversible assembly, disassembly, and reconfiguration of elliptical prism colloidal particles between liquid, nematic, and crystal states with continuously varying orientational and positional order. Accessible states are first systematically identified by varying field parameters and quantifying microstructures with nematic and crystallinity order parameters. The same order parameters vs time are used as reaction coordinates to track nonequilibrium microstructure evolution between states. A proportional feedback controller for reaction coordinate trajectories is designed to target microstructures with different degrees of order, where gain constants are tuned to maximize transition rates between states orders of magnitude faster than diffusion limited rates (on second to minute time scales). The resulting feedback control approach is demonstrated for time-dependent reaction coordinate trajectories including sinusoidal, step changes, and programmed multistate profiles. Our results and findings demonstrate a generalizable scalable approach to formally control navigation of dynamic pathways between microstructural states in a system of anisotropic colloidal particles, which can be used to control processing of particle-based materials, coatings, and devices.

  PublisherDOI

• Energy landscapes for interfacial colloidal crystallization on three-dimensional surface topographies

  Journal of Colloid and Interface Science · 2025-05-13 · 1 citations

  articleSenior authorCorresponding
  PublisherDOI

• Simple Models of Directly Measured Energy Landscapes for Different Shaped Particles in Nonuniform AC Electric Fields

  Langmuir · 2024-11-14 · 4 citations

  articleSenior authorCorresponding

  We report direct measurements of potential energy landscapes for different shaped colloidal particles interacting with nonuniform AC electric fields. Epoxy particle shapes investigated include disks, ellipses, squares, rectangles, and rhombuses, which are all part of the superelliptical prism shape class and are chosen to systematically vary particle anisotropy and corner features. The measurement configuration consists of noninteracting single particles sedimented onto microscope slides within electric fields between parallel coplanar electrodes. Thermally sampled positions and orientations of single particles in nonuniform fields are tracked in an optical microscope, and measured potential energy landscapes are obtained via Boltzmann inversions. We develop a new analytically simple model that captures all measured energy landscapes for superelliptical prism shaped colloidal particles with electrostatic double layers. The model recovers known validated potentials for spherical and ellipsoidal particles, and therefore captures energy landscapes for a variety of different colloidal particle sizes, shapes, and materials reported in prior studies.

  PublisherDOI

• Liquid, liquid crystal, and crystal states of different shaped colloids in nonuniform fields via osmotic force balance

  The Journal of Chemical Physics · 2024-12-16 · 4 citations

  articleSenior author

  We report a model to predict equilibrium density profiles for different shaped colloids in two-dimensional liquid, nematic, and crystal states in nonuniform external fields. The model predictions are validated against Monte Carlo simulations and optical microscopy experiments for circular, square, elliptical, and rectangular colloidal particles in AC electric fields between parallel electrodes. The model to predict the densities of all states of different shaped particles is based on a balance of the local quasi-2D osmotic pressure against a compressive force due to induced dipole-field interactions. The osmotic force balance employs equations of state for hard ellipse liquid, nematic, and crystal state osmotic pressures, which are extended to additional particle shapes. The resulting simple analytical model is shown to accurately predict particle densities within liquid, liquid crystal, and crystal states for a broad range of particle shapes, system sizes, and field conditions. These findings provide a basis for quantitative design and control of fields to assemble and reconfigure colloidal particles in interfacial materials and devices.

  PublisherDOI

Recent grants

• Diffusing Probes of kT-scale Specific Protein-Protein & Protein-Carbohydrate Interactions

  NSF · $324k · 2011–2015

• PECASE: Direct Measurement and Manipulation of Colloidal Interactions and Dynamics in Template Directed Photonic Crystal Assembly

  NSF · $213k · 2008–2010

• Diffusing Colloidal Probe Measurements of Protein and Synthetic Macromolecule Interactions

  NSF · $74k · 2008–2009

• Collaborative Research: CDI-Type II: First-Principles Based Control of Multi-Scale Meta-Material Assembly Processes

  NSF · $400k · 2011–2016

• Collaborative Research: Zwitterionic polymers for mucosal penetration

  NSF · $113k · 2021–2023

Frequent coauthors

• Yuguang Yang

  Tsinghua University

  30 shared

• Daniel J. Beltran-Villegas

  University of Delaware

  22 shared

• Isaac Torres‐Díaz

  University of Alabama in Huntsville

  16 shared

• David M. Ford

  13 shared

• Joëlle Fréchette

  12 shared

• Martha A. Grover

  Georgia Institute of Technology

  11 shared

• Gregg A. Duncan

  University of Maryland, College Park

  11 shared

• Tara D. Edwards

  DEVCOM Army Research Laboratory

  10 shared

Awards & honors

• Fellow of the American Chemical Society (2016)