EDUCATION  

Princeton University | Princeton, NJ

  • Ph.D. Electrical Engineering (anticipated 2017)

  • M.A. Electrical Engineering (2013)

Columbia University, School of Engineering and Applied Science | New York, NY

  • M.S. Electrical Engineering (2011)

Columbia University, Columbia College | New York, NY

  • B.A. Physics, with honors (2010)                                                                                  

 

HONORS

National Science Foundation Graduate Research Fellowship

National Merit Scholar and Presidential Scholar Nominee

Princeton University Francis Robbins Upton Fellowship

Princeton Plasma Science and Technology Fellowship

Princeton University Art of Science Competition, 3rd Prize

 

LEADERSHIP POSITIONS

Chair, Princeton Cleanroom Users Committee | 2015-present

  • Represent industry and academic user interests and manage interactions with cleanroom staff during transition to new facility

Executive Board, Princeton Graduate Women in Science and Engineering | 2014-present

  • Improve community for women in STEM via monthly social hours and science outreach events for young girls

Executive Board, Princeton University Graduate Engineering Council | 2013—present

  • Organize events for engineering school with broad attendance (150+) including talk with university president, carnival

Board Member, Princeton University Campus Iconography Committee | 2016—present

  • Identify and facilitate opportunities to provide nuanced interpretations of Princeton's history through campus art

Founder, Princeton Review of Innovation in Science and Technology | 2012—2013

  • Created funded weekly discussion group for recent topics in research with 25 members across 5 departments

Executive Board, Columbia University Science Journal | 2006-2010

  • Reviewed and edited manuscripts of original undergraduate research for peer-reviewed university publication

Leader, Columbia Outdoor Orientation Program: Hiking | 2006-2010

  • Guided incoming college freshmen on four-day self-supported backpacking trips in the Catskill Mountains

 

TEACHING AND MENTORSHIP

Teaching assistant, ELE302 (“Building Real Systems,” lab where student build robotic cars), Spring 2015 - Video link

  • Average review score from 40 students: 4.9/5

    • "Wonderfully helpful and dedicated TA"; "lifesaver" ; "Really engaged and open-minded"; Great TA who really sat down and tried to trouble shoot with you step by step and cared about you." 

Undergraduate research mentor

  • Jenny Tang, “Improving mechanical flexibility of ZnO TFTs.” (Feb 2014-present including senior thesis)
  • Abhishek Raj, “Interfacing ultrathin polyimide substrates with human collagen.” (July 2015-Sept. 2015)
  •  Vivian Yu, “A flexible, ultra-thin, and biocompatible microelectrode array.” (June 2016-present)

 

RESEARCH EXPERIENCE  

Large Area Electronics Lab | Princeton, NJ | Feb. 2012—now | Advisors: Profs. Sigurd Wagner, James Sturm, Naveen Verma

Investigating how better materials can impact circuits and systems in large area, flexible electronics

  • Spearheaded group-wide transition from a-Si to to metal-oxide semiconductors by building deposition system for ZnO and Al2O3 with 3Å resolution, developing standard, stable fabrication processes, and training students

    • Worked independently to resolve numerous technical problems and bring task to completion
    • Coordinated with distributors, suppliers, university facilities, and students to complete system
    • Calibrated film growth parameters by measuring properties of deposited films via XRD, SEM, spectroscopic ellipsometry, AFM, reflectometry, and optical profilometry
    • Identified best construction materials for vacuum system handling pyrophoric materials
    • Tool I built now benefits 10 students across 7 different research projects and 2 groups

  • Pushed boundaries for ZnO TFTs and circuits on plastic through process, material, and circuit development 

    • Experienced in deposition of materials, etching, surface treatment, and photolithography
    • Established device model for ZnO TFTs based on RPI level 61 SPICE model for a-Si TFTs
    • Demonstrated first self-aligned, in-situ passivated process by exploiting transparent oxide films
    • Characterized, modeled, and boosted (10-40X) high-frequency device parameters ft and fMAX for ZnO and a-Si TFTs
    • Implemented, designed, and simulated ZnO TFT circuits with clear frequency and/or power advantages over prior amorphous silicon (a-Si) circuits
      • Scanning circuits (current max speed 10kHz, 10X enhancement over a-Si)
      • Colpitts LC oscillators (current max speed 5.45MHz, previously unachieved with a-Si)
      • Cross-coupled LC oscillators (current max speed 35MHz, fastest circuits to date made <200oC)
    • Built fast, flexible ZnO circuits on 50μm-thick freestanding and ultrathin 3.5μm-thick spin-cast polyimide
      • Demonstrated 17MHz cross-coupled oscillators on ultrathin (3.5μm-thick) plastic - fastest circuits entirely <200C
      • Investigated impact of mechanical strain on ZnO thin-film transistors on plastic substrates
      • Developed ZnO TFTs that can bend <500μm without mechanical fatigue or electrical variation

  • Integrated thin-film circuits, sensors, custom PCBs, and signal processing to create a full pressure-sensing system

    • Architecture, based on ZnO-TFT digitally-controlled oscillator, demonstrates clear scaling advantage over active matrices
    • Designed, analyzed, and fabricated circuits, designed PCBs, built measurement setup, and automated measurements
    • Overcame TFT variability by injection-locking oscillators to reference signal
    • Reconstructed pressure sensor data demonstrates very low system acquisition error: <0.27%

  

Columbia Lab for Unconventional Electronics | New York, NY | Sep. 2010—Sep. 2011 | Advisor: Prof. Ioannis (John) Kymissis

 Explored potential for power harvesting from ambient light energy  

  • Developed novel testbed for accurate, dynamic analysis of photovoltaic indoor light harvesting efficiency  
  • Designed active-matrix organic transistor/organic photovoltaic array for indoor energy harvesting
    • Experienced in depositing organic materials: ink-jet printing TIPS-pentacene, CVD parylene

 

MIT Lincoln Laboratory | Lexington, MA | Jul.—Aug. 2010 | Advisor: Dr. Audrey Dumanian

Simulated complex geometrical objects under EM illumination for radar applications

  • Used FEKO and Matlab for simulations

 

Columbia University Department of Physics | New York, NY | Mar. 2009—May 2010 | Advisor: Prof. Emlyn Hughes

Built up lab (from non-existence) for experiments using polarized He-3 gas for medical imaging

  • Completed construction of all component parts required to polarize helium-3

 

MIT Francis Bitter Magnet Laboratory | Cambridge, MA | Jun.—Aug. 2005, 2007, 2008 | Advisor: Dr. Jagadeesh Moodera

Fabricated, evaluated organic transistors and silver sulfide atomic switches as NSF REU funded intern

  • Determined optimal growth conditions for Ag2S crystalline films via material analysis techniques
  • Built organic transistors using thermally evaporated rubrene semiconductor

 

PUBLICATIONS AND PRESENTATIONS

FIRST AUTHOR

Y. Afsar, T. Moy, N. Brady, S. Wagner, J. C. Sturm, N. Verma, "Large-scale Acquisition of Large-area Sensors Using an Array of Frequency-Hopping ZnO Thin-Film-Transistor Oscillators," Accepted to the IEEE International Solid-State Circuits Conference, February 2017, San Francisco, CA.

 

Y. Afsar, J. Tang, W. Rieutort-Louis, L. Huang, Y. Hu, J. Sanz-Robinson, N. Verma, S. Wagner, J. C. Sturm, Impact of Bending on Flexible Metal Oxide TFTs and Oscillator Circuits. Journal of the Society for Information Display, 24:371-380. doi: 10.1002/jsid.445. (INVITED) - PDF Link

 

Y. Afsar, J. Tang, W. Rieutort-Louis, N. Verma, S. Wagner, J. C. Sturm, "'Oxide-TFT LC Oscillators on Glass and Plastic for Wireless Functions in Large-Area Flexible Electronic Systems," Society for Information Display 2016 Symposium, May 2016, San Jose, CA. (OUTSTANDING PAPER NOMINATION) - PDF Link

 

Y. Afsar, W. Rieutort-Louis, N. Verma, S. Wagner, J. C. Sturm, "ZnO versus a-Si thin-film oscillator circuits for hybrid integration: metrics for design and comparison,” 15th Annual Flexible & Printed Electronics Conference (FLEX2016), March 2016, Monterey, CA. (FIRST PLACE STUDENT POSTER) - PDF Link

 

Y. Afsar, W. Rieutort-Louis, Y. Hu, L. Huang, J. Sanz-Robinson, N. Verma, J. C. Sturm, S. Wagner, "10-MHz cross-coupled LC oscillators based on plasma-enhanced ALD ZnO thin-film transistors," Materials Research Society Meeting, April 2015, San Francisco, CA. - PDF Link

 

Y. Afsar, W. Rieutort-Louis, N. Verma, J. C. Sturm, S. Wagner, "Apparent super-linear behavior of cutoff frequency in PEALD ZnO TFTs," International Thin Film Transistor Conference, Feb 2015, Rennes, France. - PDF Link

 

Y. Afsar, W. Rieutort-Louis, N. Verma, J. C. Sturm, S. Wagner, "fMAX and fT measurements of PEALD ZnO TFTs for high-frequency oscillators," Materials Research Society Meeting, November 2014, Boston, MA. - PDF Link

 

Y. Afsar, T. Moy, N. Verma, J. C. Sturm, S. Wagner, "Plasma-Enhanced Atomic Layer Deposition Zinc Oxide Thin-Film Transistor-Based Scanning Circuits," International Workshop on Zinc Oxide and Related Materials, September 2014, Niagara Falls, Canada. - PDF Link

 

Y. Afsar, S. Avasthi, J. C. Sturm, N. Verma, S. Wagner, "Self aligned and in-situ passivated ZnO TFTS," International Thin Film Transistor Conference, January 2014, Delft, Netherlands. - PDF Link

 

Y. Afsar, J. Sarik, M. Gorlatova, G. Zussman, I. Kymissis, “Evaluating photovoltaic performance indoors,” IEEE Photovoltaics Specialists Conference, June 2012, Austin, TX. - PDF Link

 

SECOND AUTHOR 

N. Verma, Y. Afsar, L. Huang, Y. Hu, T. Moy, W. Rieutort-Louis, J. Sanz-Robinson, S. Wagner, J. C. Sturm, "Creating a Thin-film Electronics Roadmap for Flexible-Hybrid Systems,” 15th Annual Flexible & Printed Electronics Conference (FLEX2016), March 2016, Monterey, CA.

 

L. Aygun, Y. Afsar, N. Verma, S. Wagner, J. C. Sturm, "High-frequency ZnO schottky diodes for inductive non-contact interfaces for hybrid flexible electronics/IC integration,” 15th Annual Flexible & Printed Electronics Conference (FLEX2016), March 2016, Monterey, CA.

 

W. Rieutort-Louis, Y. Afsar, J.C. Sturm, N. Verma, S. Wagner, "Representative Flicker Noise Measurements for Low-Temperature Amorphous Silicon, Organic, and Zinc Oxide Thin-Film Transistors," International Thin Film Transistor Conference, February 2015, Rennes, France.

 

I.C. Lekshmi, Y. Afsar, J. S. Moodera. “Metal-semiconductor-metal junctions with silver sulphide barrier layers,” APS March Meeting, March 2006, Baltimore, MD.

 

CONTRIBUTING AUTHOR 

S. Wagner, T. Moy, J. Sanz-Robinson, W. Rieutort-Louis, Y. Afsar, Y. Hu, L. Huang, J. C. Sturm, N. Verma, “Thin-Film Technology for Large-Area / CMOS Hybrid Systems,” PRIME: Pacific Rim Meeting on Electrochemical and Solid-State Science, October 2016, Honolulu, HI.

 

L.E. Aygun, N. Verma, Y. Afsar, Y. Hu, L. Huang, T. Moy, J. Sanz-Robinson, W. Rieutort-Louis, S. Wagner, J.C. Sturm, "Hybrid Large-Area Systems and Their Interconnection Backbone," International Symposium on Networks-on-Chip (NOCS), September 2016, Nara, Japan.

 

J. C. Sturm, J. Sanz-Robinson, H. Jia, W. Rieutort-Louis, Y. Hu, L. Huang, Y. Afsar, T. Moy, "A Natural Human-Machine Interface via a Flexible Hybrid Sheet for Remote Gesture Sensing and Speaker Isolation," 15th Annual Flexible & Printed Electronics Conference (FLEX2016), March 2016, Monterey, CA.

 

S. Wagner, T. Moy, J. Sanz-Robinson, W. Rieutort-Louis, Y. Afsar, Y. Hu, L. Huang, J. C. Sturm, N. Verma, “Thin-Film Devices for Large-Area / CMOS Hybrid Systems,” International Thin Film Transistor Conference, February 2016, Hsinchu, Taiwan.

 

W. Rieutort-Louis, J. Sanz-Robinson, T. Moy, L. Huang, Y. Hu, Y. Afsar, J. C. Sturm, N. Verma, S. Wagner, "Integrating and Interfacing Flexible Electronics in Hybrid Large-Area Systems," IEEE Trans. Components, Packaging and Manufacturing Technology (TCPMT), vol. 5, no. 9, pp. 1219-1229, Sept. 2015. (Invited)

 

S. Wagner, J. Sanz-Robinson, W. Rieutort-Louis, L. Huang, T. Moy, Y. Hu, Y. Afsar, J. C. Sturm, N. Verma, “Investigating the Architecture of Flexible Large-Area Hybrid Systems,” Information Display, Vol. 31, No. 4, July/Aug 2015.

 

W. Rieutort-Louis, L. Huang, Y. Hu, J.Sanz Robinson, Y. Afsar, J. C. Sturm, N. Verma, and S. Wagner, “Characterization of Amporphous Silicon Thin-Film Transistor Cutoff Frequency,” Device Research Conference, June 2014, Santa Barbara, CA.

 

S. Avasthi, W. McClain, Y. Afsar, G. Man, J. Jhaveri, K. Nagamatsu, A. Kahn, J. Schwarz, S. Wagner, J. C. Sturm, "Hole-Blocking Metal-Oxide/Crystalline-Silicon Heterojunctions with Recombination Velocity of < 100 cm/s," Materials Research Society Meeting, April 2014, San Francisco, CA

 

I. C. Lekshmi, G. Berera, Y. Afsar, G. X. Miao, T. Nagahama, T. Santos, and J. S. Moodera, “Controlled synthesis and characterization of Ag2S films with varied microstructures and its role as asymmetric barrier layer in trilayer junctions with dissimilar electrodes.” J. Appl. Phys., 103, 093719 (2008).

 

A. C. Greenwald, I. Puscasu, M. McNeal, E. Johnson, J. T. Daly, M. U. Pralle, and Y. Afsar, “Ferroelectric Modulation of 2-D Photonic Crystal Emission for Gas Detection.” MRS Fall Meeting, November 2006, Boston, MA.

 

RELEVANT COURSEWORK

VLSI, Biomedical Circuits, Electronic Devices, Electronic Materials, Characterization of Materials, Intro to Nanotechnology

Solid State Physics, Quantum Mechanics, Implementations of Quantum Information, Thermal Physics, Probability and Stochastics

Electricity & Magnetism, Electromagnetic Waves & Optics, Photonics, Lightwave Devices, Applied Quantum Optics

Microelectromechanical Systems (MEMS), Mechanics

Solar Thermal Engineering, Physics of Solar Energy, Solar Energy and the Smart Grid

Intro to Computer Science/Programming in C

Complex Analysis, Partial Differential Equations, Ordinary Differential Equations

 

ADDITIONAL SKILLS 

Programming & Technical Software: Matlab, Labview, some C, Cadence, SPICE, Altium, L-Edit, PSoC

Hands-on: Soldering, Micro/nano fabrication, Machine Shop certification, Microcontrollers (PSoC)

Languages: English (native), Bengali, German (int.), French (int. reading), Latin (reading)

U.S. Citizenship