NSF CAREER Award for in situ gelation in confined flows

April 5, 2023: Prof. Hashmi’s proposal, “CAREER: in situ polymer gelation in confined flows” has been funded by the NSF!  The research will generate new fundamental understanding of the intermittency that can occur when polymers gel while flowing through small channels, like nozzles used for 3D and bio-printing.  The Award will feature educational and outreach opportunities like curricular development for high school science teachers and research engagement for undergraduate and high school students.

Provost OGS & MIE Awards for Saeed Alborzi

March 31, 2023: Saeed Alborzi has been awarded two prestigious honors from the Northeastern University Provost Office and the MIE Department.  The Outstanding Graduate Student Experiential Award (OGS) from the Provost comes with a $1,000 prize and will be presented Thursday, April 20.  The MIE Department’s Akira Yamamura Award for Excellence in Research also recognizes Saeed’s accomplishments as a graduate student and during his co-op internship at Amgen.  Congratulations, Saeed!

Preprint: Markov process in colloidal clogging of tapered pores

March 23, 2022: Kayode Majekodunmi’s preprint, “Discontinuous clogging in gently tapered microchannels reveals a transient Markov process,” has been posted on Research Square.   A qualitatively novel statistical mechanism describes colloidal clogging in pores that taper gently to a narrow exit.  Instead of growing continuously, clogs stop growing when a new clog forms upstream.  As such, the Poisson process often used to describe colloidal clogging no longer provides a complete picture.

Arch geometry of hopper clogs

February 1, 2023: Saeed Alborzi’s paper with David Abrahamyan, “Particle rigidity and friction enable variable arch geometry to cause clogging” has been published in Physical Review E.  We measure a variety of geometric features of arches which clog a hopper in granular flow.  As the fraction of rigid particles increases compared to soft, the range of geometric configuration options for the arch increases, providing an explanation for the more frequent clogging found in rigid particle systems.

Rigid particles clog tapered channels in a discontinuous fashion

December 30, 2022: Kayode Majekodunmi’s paper “Flow dynamics through discontinuous clogs of rigid particles in tapered microchannels” has been published in Scientific Reports.  Clogging of rigid particles in tapered channels occurs in a discontinuous fashion.  This causes the resulting flow rate through the clogged channels to decrease significantly more slowly than flow through continuously clogged channels.  Our results have implications for multi-stage filter designs.

Migration in dilute emulsion flows

December 23, 2022: Sabrina Marnoto’s paper, “Application of droplet migration scaling behavior to microchannel flow measurements,” has been published in Soft Matter.  In it, we measure the cross-stream migration of emulsion drops in microfluidic flows, and present parametric scaling arguments to understand migration in terms of droplet size, channel height, flow rate, and fluid viscosity.  These results can inform the design of particles for consumer products, including drug delivery particles, which must flow near a (blood vessel) channel wall to deliver their therapeutic cargo.

Soft particles facilitate flow of rigid particles in a 2D hopper

May 12, 2022: Saeed Alborzi’s paper with Ben Clark has been published in Soft Matter.  We measure clogging probability in a rotating hopper as a function of both the fraction of soft particles (E~35kPa) compared to rigid particles and the particle sizes.  Increasing the fraction of soft particles greatly mitigates clogging, with experimental results corroborated by simulations.

New England Complex Fluids Workshop at Northeastern University

March 11, 2022: Experts from the academic and industrial research community studying soft matter and complex fluids convened in the Raytheon Ampitheater in Egan for the 90th NECF workshop and a full day of invited talks and sound bite updates from around the region.  Invited speakers: Jesse Ault, Brown University; Leila Deravi, Northeastern; Tony Dinsmore, UMass Amherst; and Ryan Poling-Skutvik, URI.

A Machine Learning and Computer Vision Approach to Rapidly Optimize Multiscale Droplet Generation

January 13, 2022: Evy Shaulsky’s work with lead author Alex Siemenn in a collaboration with the Drori and Buonassissi labs at MIT has been published in ACS Applied Materials & Interfaces.  In it, we present a machine learning system to assist users of microfluidic droplet makers to quickly achieve the desired size and throughput of droplets.

Publication on the arXiv

A collaboration with two groups from MIT, “Autonomous optimization of fluid systems at varying length scales” has been published on  In it, we present an AI platform that optimizes droplet formation in both microfluidic droplet makers and inkjet printing, using a user-defined optimization function.

Congratulations to Saeed & Sabrina!

In May, 2021, Saeed passed his Oral Exam.  In June, Sabrina passed her Proposal Defense and advanced to PhD candicacy.  Congratulations to them both!

ACS Colloids Conference, 2021

Evy presented his talk, “Enhancing control parameter space investigation in flow-focusing droplet generation,” at the ACS Colloids Conference in June.