Benjamin Yellen

Image of 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:

  • Ph.D. Drexel University, 2004

Curriculum Vitae
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

Awards, Honors, and Distinctions:

    Courses Taught:
    • EGR 244L: Dynamics
    • ME 391: Undergraduate Projects in Mechanical Engineering
    • ME 555: Advanced Topics in Mechanical Engineering

    Representative Publications: (More Publications)
      • Abedini-Nassab, R; Murdoch, DM; Kim, C; Yellen, BB, Optimization of magnetic switches for single particle and cell transport, Journal of Applied Physics, vol 115 no. 24 (2014), pp. 244509-244509 [10.1063/1.4884609] [abs].
      • Tahir, MA; Nori, F; Yellen, BB, Dynamically-tunable colloidal band-pass and band-gap filters, Journal of Applied Physics, vol 115 no. 13 (2014), pp. 134902-134902 [10.1063/1.4870041] [abs].
      • Lim, B; Reddy, V; Hu, X; Kim, K; Jadhav, M; Abedini-Nassab, R; Noh, YW; Lim, YT; Yellen, BB; Kim, C, Magnetophoretic circuits for digital control of single particles and cells., Nature Communications, vol 5 (2014) [10.1038/ncomms4846] [abs].
      • Ferris, R; Yellen, B; Zauscher, S, Electric double layer formed by polarized ferroelectric thin films: Implications for sensing and colloidal manipulation in aqueous media, ACS National Meeting Book of Abstracts, vol 246 (2013) [abs].
      • Ferris, RJ; Lin, S; Therezien, M; Yellen, BB; Zauscher, S, Electric double layer formed by polarized ferroelectric thin films., ACS Applied Materials and Interfaces, vol 5 no. 7 (2013), pp. 2610-2617 [10.1021/am3031954] [abs].