Benjamin B. Yellen

Benjamin Yellen

Associate Professor in the Department of Mechanical Engineering and Materials Science

Yellen's group is interested in developing highly parallel mechanisms for controlling the transport and assembly of ensembles of objects ranging from micron-sized colloidal particles to single cells.  As of 2013, Professor Yellen is active in two main areas of research:
1) Development of single cell analysis tools using magnetic circuits. The goal of this project is to develop an automated single cell analysis platform that allows for highly flexible and highly parallel manipulation of single cells. Our approach draws inspiration from electronic circuit theory through the development highly flexible methods for transporting particles above magnetic thin film patterns either reversibly (conductor) or irreversibly (rectifier), storing cells in well-defined regions of space either temporarily (capacitor) or permanently (data storage), switching current pathways at selected junctions (transistor) and coordinating a large set of electronic functions with few input wires (multiplexer). When combined with microfluidic systems that allow for repeated doses of pharmaceuticals, we will have a developed a platform that is ripe to have a major impact on the field of HIV eradication and cancer suppression.
2) Multiparticle assembly of colloidal crystals. The goal of this project is to understand the formation and phase transitions occuring inside single crystals composed of alloys of colloidal particles.  Here, we are interested in observing crystals forming from magnetic and non-magnetic colloidal particles dispersed inside ferrofluid.  We are just beginning to solve the questions of how to grow large single crystals, and how to transform these crystals by tilting of an external magnetic field.  The results of this project will serve as useful models for understanding how crystals form and transform in the corollary atomic scale materials in nature.

Appointments and Affiliations

  • Associate Professor in the Department of Mechanical Engineering and Materials Science
  • Associate Professor of Biomedical Engineering

Contact Information

  • Office Location: CIEMAS 3389, Durham, NC 27708
  • Office Phone: (919) 660-8261
  • Email Address:
  • Websites:


  • Ph.D. Drexel University, 2004

Research Interests

Our group currently has two main research activities. Project #1. Development of single cell random access memory. The goal of this project is to develop an automated system for reading and writing single cells (e.g., immune cells, yeast cells, etc.) to arbitrary sites on a micro fabricated chip. We then plan to query the behavior of single cells in response to pharmaceutical compounds and their interactions with other single cells. Finally, we are developing automated tools to extract single cells from the array for follow on gene analysis. Project #2. Phase transformations and dynamics in colloidal systems. The goal of this project is to study ensemble behavior in dense suspensions of magnetic colloidal particles. In particular, we are interested in studying phase transformations in alloys of magnetic and non-magnetic particles immersed in a ferrofluid. We are also interested in domain growth, and far from equilibrium behavior.


Micro-electronic mechanical machines
Nanomaterial manufacturing and characterization
Nonlinear Dynamics
Computational Electromagnetics
Soft materials
Biological Materials
Active materials
Heat and mass transfer
Drug Delivery

Courses Taught

  • EGR 244L: Dynamics
  • ME 391: Undergraduate Projects in Mechanical Engineering
  • ME 392: Undergraduate Projects in Mechanical Engineering
  • ME 517: Electromagnetic Processes in Fluids
  • ME 555: Advanced Topics in Mechanical Engineering

In the News

Representative Publications

  • Abedini-Nassab, R; Joh, DY; Albarghouthi, F; Chilkoti, A; Murdoch, DM; Yellen, BB, Magnetophoretic transistors in a tri-axial magnetic field., Lab on a Chip, vol 16 no. 21 (2016), pp. 4181-4188 [abs].
  • Pham, AT; Seto, R; Schönke, J; Joh, DY; Chilkoti, A; Fried, E; Yellen, BB, Crystallization kinetics of binary colloidal monolayers., Soft Matter, vol 12 no. 37 (2016), pp. 7735-7746 [10.1039/c6sm01072e] [abs].
  • Ohiri, KA; Evans, BA; Shields, CW; Gutiérrez, RA; Carroll, NJ; Yellen, BB; López, GP, Magnetically Responsive Negative Acoustic Contrast Microparticles for Bioanalytical Applications., ACS Applied Materials and Interfaces, vol 8 no. 38 (2016), pp. 25030-25035 [10.1021/acsami.6b09591] [abs].
  • Shields Iv, CW; Wang, JL; Ohiri, KA; Essoyan, ED; Yellen, BB; Armstrong, AJ; López, GP, Magnetic separation of acoustically focused cancer cells from blood for magnetographic templating and analysis., Lab on a Chip, vol 16 no. 19 (2016), pp. 3833-3844 [abs].
  • Abedini-Nassab, R; Joh, DY; Van Heest, M; Baker, C; Chilkoti, A; Murdoch, DM; Yellen, BB, Magnetophoretic Conductors and Diodes in a 3D Magnetic Field., Advanced Functional Materials, vol 26 no. 22 (2016), pp. 4026-4034 [10.1002/adfm.201503898] [abs].