About

Anthony Dinsmore is a Professor of Physics at UMass Amherst specializing in soft matter physics. His research focuses on fundamental principles and the development of new materials within the realm of soft matter, including colloids, emulsions, membranes, and granular materials. He primarily conducts experimental work to explore these areas. Professor Dinsmore leads the Dinsmore Research Group, which investigates various aspects of soft matter physics, with current projects detailed under the "Research" tab on his group’s webpage. His work involves studying phenomena such as contact angle hysteresis and the mechanics of lipid bilayer membranes, contributing to the understanding of material properties and behaviors at interfaces. His group includes graduate and undergraduate students engaged in related experimental studies, reflecting his commitment to mentoring and advancing research in soft matter physics.

Research topics

• Materials science
• Chemistry
• Composite material
• Organic chemistry
• Chemical engineering
• Geology
• Biophysics
• Mechanics
• Classical mechanics
• Biochemistry
• Physics
• Chemical physics
• Inorganic chemistry

Selected publications

• Mechanical performance of hybrid polymer–lipid vesicles with leaflet asymmetry engineered using microfluidics

  Proceedings of the National Academy of Sciences · 2026-03-06

  articleOpen access

  Lipid vesicles consist of aqueous cores surrounded by a bilayer of phospholipids. Hybrid polymer-lipid vesicles incorporate both polymers and lipids, offering promising properties for developing pharmaceuticals, biosensors, and artificial cells. The hybrid vesicles can be symmetric, with two leaflets of identical compositions, or asymmetric, in with leaflets of dissimilar compositions, which can lead to dramatically altered properties. However, existing methods for producing symmetric and asymmetric hybrid vesicles often result in heterogenous compositions and sizes, making it challenging to quantify the effect of asymmetry and limiting applications. Here, we use a microfluidic approach to produce hybrid vesicles with either symmetric or asymmetric leaflets and precisely engineered compositions. We find that the vesicles with asymmetric leaflets are significantly stiffer and tougher than those with symmetric leaflets; moreover, the lateral diffusivity of lipids is greatly decreased. The structure for improved toughness consists of a stretchable lipid inner leaflet and a fully continuous polymer outer leaflet. This approach to precisely engineer asymmetric structures can be applied to hybrid vesicles composed of block copolymers and phospholipids soluble in chloroform and hexane, further expanding their applications.

  PublisherDOI

• Data from: Mechanical performance of hybrid polymer-lipid vesicles with leaflet asymmetry engineered using microfluidics

  Open MIND · 2026-02-14

  dataset

  Lipid vesicles consist of aqueous cores surrounded by a bilayer of phospholipids. Hybrid polymer–lipid vesicles incorporate both polymers and lipids, offering promising properties for developing pharmaceuticals, biosensors, and artificial cells. The hybrid vesicles can be symmetric, with two leaflets of identical compositions, or asymmetric, with leaflets of dissimilar compositions, which can lead to dramatically altered properties. However, existing methods for producing symmetric and asymmetric hybrid vesicles often result in heterogeneous compositions and sizes, making it challenging to quantify the effect of asymmetry and limiting applications. Here, we use a microfluidic approach to produce hybrid vesicles with either symmetric or asymmetric leaflets and precisely engineered compositions. We find that the vesicles with asymmetric leaflets are significantly stiffer and tougher than those with symmetric leaflets; moreover, the lateral diffusivity of lipids is greatly decreased. The structure for improved toughness consists of a stretchable lipid inner leaflet and a fully continuous polymer outer leaflet. This approach to precisely engineer asymmetric structures can be applied to hybrid vesicles composed of block copolymers and phospholipids soluble in chloroform and hexane, further expanding their applications.

  DOI

• Delamination and restructuring inside multilamellar lipid vesicles by a polycation: formation of multi-compartment vesicles

  Soft Matter · 2026-01-01

  articleSenior authorCorresponding

  , vesicular superparticles. Using giant multilamellar vesicles, we report time-lapse observations of the formation process and also of the breakup process after the polymer is diluted at constant osmotic stress. We show the results of a range of polymer molecular weights and concentrations. We present a simple model that predicts conditions of delamination owing to a competition between electrostatic repulsion among the polymers and the bending elasticity of the membranes. The results pave the way to a new kind of response mechanism in multilamellar vesicles that might lead to soft materials that can change their stiffness or topology on demand.

  PublisherDOI

• Geometry Dependence of the Receding Angle of a Droplet on a Solid Cylindrical Surface

  Langmuir · 2025-04-21

  articleSenior authorCorresponding

  Droplets that partially wet solid surfaces exhibit hysteresis in their contact angle. The values of the minimum (receding) and maximum (advancing) angles, θR and θA, are empirically well-defined and thought to be unique for a given set of materials. We measured the contact angles of water droplets hanging from hydrophobic, PDMS-functionalized glass and found that the value of θR varies with the curvature of the glass. The effect is substantial: θR changes from 86.0 ± 1.9° on a flat plate to 95.6 ± 1.9° on a 2 mm diameter rod of the same material. The measured values of θA were independent of geometry (θA = 103.2 ± 0.9°). We found a consistent trend among PDMS-functionalized glass cylinders with diameters ranging from 2 to 12.7 mm. We also measured the speed at which the contact line moved just after receding; these results showed a receding speed ∝ cos(θR) – cos(θE) and a consistent equilibrium contact angle, θE = 103.4 ± 2.3°. Finally, we measured the sliding of water droplets as rods were tilted. The larger θR (and thus smaller hysteresis) for a 2 mm-diameter rod led to droplets sliding at a tilt angle of just 21° from horizontal, compared to the 48° minimum tilt for a 7 mm rod. The results show that hysteresis arises from an energy barrier that depends on the shape of the droplet and contact line, both of which change with substrate curvature. The results may lead to designing surfaces that better trap water droplets or shed them for self-cleaning or water-harvesting applications.

  PublisherDOI

• Mechanical performance of hybrid polymer-lipid vesicles with leaflet asymmetry engineered using microfluidics

  ArXiv.org · 2025-09-02

  preprintOpen access

  Lipid vesicles consist of aqueous cores surrounded by a bilayer of phospholipids. Hybrid polymer-lipid vesicles incorporate both polymers and lipids, offering promising properties for developing pharmaceuticals, biosensors, and artificial cells. The hybrid vesicles can be symmetric, in which their two leaflets contain identical compositions, or asymmetric, in which the leaflets possess dissimilar compositions and can lead to dramatically modified properties. However, methods to produce both symmetric and asymmetric hybrid vesicles result in heterogenous compositions and sizes, making it challenging to quantify the effect of asymmetry and limiting applications. Here, we use a microfluidic approach to produce hybrid vesicles containing symmetric or asymmetric leaflets with precisely engineered compositions. We find the vesicles with asymmetric leaflets are significantly stiffer and tougher than those with symmetric leaflets; moreover, the lateral diffusivity of lipids is greatly decreased. The structure for improved toughness consists of an inner leaflet that is a stretchable lipid leaflet and an outer leaflet that is a fully continuous polymer leaflet. This technique of precisely engineering asymmetric structures may be applied to hybrid vesicles composed of block copolymers and phospholipids dissolvable in chloroform and hexane, further expanding their applications.

  PublisherOA PDFDOI

• Structural and Mechanical Response of Two-Component Photoswitchable Lipid Bilayer Vesicles

  Langmuir · 2023-11-03 · 11 citations

  articleSenior authorCorresponding

  Optical control of phospholipids is an attractive option for the rapid, reversible, and tunable manipulation of membrane structure and dynamics. Azo-PC, a lipid with an azobenzene group within one acyl chain, undergoes a light-induced trans-to-cis isomerization and thus arises as a powerful tool for manipulating lipid order and dynamics. Here, we report on vesicle-scale micropipette measurements and atomistic simulations to probe the elastic stretching modulus, water permeability, toughness, thickness, and membrane area upon isomerization. We investigated both dynamics and steady-state properties. In pure azo-PC membranes, we found that the molecular area in trans was 16% smaller than that in cis, the membrane’s stretching modulus kA was 2.5 ± 0.3 times greater, and the water permeability PW was 3.5 ± 0.5 times smaller. We also studied mixtures of azo-PC with the miscible, unsaturated lipid DOPC. Atomistic molecular dynamics simulations show how the membrane thickness, chain order, and correlations across membrane leaflets explain the experimental data. Together, these data show how one rotating bond changes the molecular- and membrane-scale properties. These results will be useful for photopharmacology and for developing new materials whose permeability, elasticity, and toughness may be switched on demand.

  PublisherDOI

• Consequences of Noncovalent Interfacial Contacts between Nanoparticles and Giant Vesicles

  Angewandte Chemie · 2022-07-01

  articleOpen access

  Abstract Biological membrane fluidity enables shape reform upon a functionally complementary encounter between a biomolecule and a synthetic nanoparticle. Nanomedicine uses ligand‐cell surface receptor affinities for nanoparticle targeting. However, due to toxicity concerns, the nature of the nanoparticle–biomembrane interaction needs exploration to realize ligand surface density and receptor–ligand interaction effects on subsequent uptake/other interaction outcomes. In this study, giant unilamellar vesicles (GUVs) were surface‐immobilized with a hCAII model receptor to study nanoparticle–complementary surface ligand interactions. We find interaction strength impacts morphological outcomes, namely, inter‐GUV adhesion, lysis, and GUV swallowing. Nanoparticle size, receptor/ligand surface densities, overall receptor/ligand concentrations and ratios affect the strength of adhesion, and thus the outcome. Interaction energy effects on GUV morphological outcomes offer fundamental insights into the design of abiological materials for interacting with biological materials.

  PublisherOA PDFDOI

• Adsorption of Hydrophilic Silica Nanoparticles at Oil–Water Interfaces with Reversible Emulsion Stabilization by Ion Partitioning

  Langmuir · 2022 · 13 citations

  Senior authorCorresponding
  • Chemical engineering
  • Chemistry
  • Inorganic chemistry

  ) migrate into the water phase and leave behind a net positive charge in the oil. Our results show how a large class of inorganic hydrophilic, anionic nanoparticles can be used to stabilize emulsions in a reversible and stimulus-responsive way, without surface modifications.

  PublisherDOI

• Consequences of Noncovalent Interfacial Contacts between Nanoparticles and Giant Vesicles

  Angewandte Chemie International Edition · 2022-07-01 · 9 citations

  article

  Abstract Biological membrane fluidity enables shape reform upon a functionally complementary encounter between a biomolecule and a synthetic nanoparticle. Nanomedicine uses ligand‐cell surface receptor affinities for nanoparticle targeting. However, due to toxicity concerns, the nature of the nanoparticle–biomembrane interaction needs exploration to realize ligand surface density and receptor–ligand interaction effects on subsequent uptake/other interaction outcomes. In this study, giant unilamellar vesicles (GUVs) were surface‐immobilized with a hCAII model receptor to study nanoparticle–complementary surface ligand interactions. We find interaction strength impacts morphological outcomes, namely, inter‐GUV adhesion, lysis, and GUV swallowing. Nanoparticle size, receptor/ligand surface densities, overall receptor/ligand concentrations and ratios affect the strength of adhesion, and thus the outcome. Interaction energy effects on GUV morphological outcomes offer fundamental insights into the design of abiological materials for interacting with biological materials.

  PublisherDOI

• Vesicle-Based Gel via Polyelectrolyte-Induced Adhesion: Structure, Rheology, and Response

  Langmuir · 2021 · 12 citations

  Senior authorCorresponding
  • Chemical engineering
  • Materials science
  • Chemistry

  We describe an experimental study of soft solids composed of micron-scale lipid bilayer vesicles that adhere to one another through electrostatic attraction to an oppositely charged polymer (PDADMAC). As the polymer concentration was increased, we found a fluid phase, a solid gel phase, and a gel composed of internally reorganized vesicles. Optical microscopy images showed a nearly close-packed structure of adhered vesicles that retained their closed-cell morphology. Shear rheology measurements showed that the gel phase is a solid with a modulus at the Pa scale and with linear response up to 70% strain. We found that the modulus depends on the energy per area of membrane–membrane adhesion but does not depend on the vesicle size. We further found that the gels survived osmotic stress or dilution of the adhering polymer but could be rapidly disrupted in response to the addition of strongly binding silica nanoparticles. These results demonstrate the potential for cell-sized lipid vesicles to form a solid platform that maintains the responsive properties of the membranes. Such materials may find applications as triggerable, protective coatings of delicate surfaces.

  PublisherDOI

Recent grants

• Force Maps, Aging, and Elasticity in Random, Non-Equilibrium Solids

  NSF · $345k · 2006–2009

• Particles on Curved Liquid Interfaces: Geometry, Mechanics, and Self-Assembly

  NSF · $300k · 2010–2014

• Mechanics of Interfacial Assemblies

  NSF · $328k · 2014–2018

• Contact Angle Hysteresis on Curved Surfaces

  NSF · $337k · 2018–2022

• Imaging the Dynamics of Freezing and Melting with Colloids

  NSF · $400k · 2009–2014

Frequent coauthors

• John R. K. Savage

  24 shared

• R. A. Guyer

  Los Alamos National Laboratory

  18 shared

• Manuel Márquez

  STgenetics (United States)

  18 shared

• Banahalli R. Ratna

  18 shared

• Arjun G. Yodh

  University of Pennsylvania

  18 shared

• S. B. Qadri

  United States Naval Research Laboratory

  17 shared

• Todd Emrick

  University of Massachusetts Amherst

  17 shared

• David A. Weitz

  Harvard University

  17 shared

Labs

• Dinsmore Research GroupPI

  Soft matter physics, such as colloids, emulsions, membranes, and granular materials, with a focus on fundamental principles and new materials.