Sean O'Hern
Sean C. O'Hern, Ph.D., P.E., CFEI, LEED® AP
Senior Engineer
Thermal Sciences
Natick

Dr. O'Hern specializes in the mechanical engineering analysis of fluid and thermal processes, systems, and products. He applies his expertise in the investigation and prevention of failures, review of product and system performance, assessment of regulatory compliance, investigation of patent and intellectual property disputes, and review of design requirements and specifications. He also provides origin and cause analysis in fire and explosion investigations and is an integral member of Exponent’s Combustible Dust Testing Laboratory. Dr. O’Hern consults in a variety of industries, including construction, oil and gas, food and beverage, biotech/biopharma, chemical, and consumer products. His project experience includes the analysis of aerosol cans, propane tanks, outdoor gas appliances, consumer home appliances, boilers, heat exchangers, expansion tanks, gas piping, hydronic piping and equipment, flue pipes, refrigerators, medical devices, and LNG facilities.

Dr. O'Hern is an experienced heating, ventilation, and air-conditioning (HVAC) professional engineer and has designed climate control solutions for surgery centers, schools, commercial buildings, warehouses, police stations, and mixed-use facilities. He is a member of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) and sits on the Technical Committee for Building Energy Performance. Dr. O’Hern is a member of both the Environment and Energy Efficiency Committee and the School Building Committee for Watertown, Massachusetts. As a certified Leadership in Energy and Environmental Design - Accredited Professional (LEED® AP), he is an experienced building energy modeler.

Prior to joining Exponent, Dr. O'Hern was a graduate research assistant in the Micro and Nanofluidics Research Group in the Department of Mechanical Engineering at the Massachusetts Institute of Technology. At MIT, Dr. O'Hern led research efforts to investigate nanoporous graphene for use as a high performance membrane for water purification, desalination, biological separation, and gas separation. His work has been highlighted in numerous media outlets including MIT News and Wired.com. Dr. O’Hern has one granted patent and one pending patent on graphene membrane technology. His scientific and engineering background includes fluid mechanics, heat and mass transport processes, ion transport processes, thermodynamics, electrokinetics, reaction kinetics, and interfacial phenomena. Dr. O'Hern is skilled in materials characterization (SEM, TEM, UV-vis, XRD, XPS, Raman, confocal fluorescence microscopy), nanofabrication (ALD, CVD, FIB, wet etching), modeling and simulation, and design of experiments.

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Mechanical Engineering, Massachusetts Institute of Technology (MIT), 2015
  • S.M., Mechanical Engineering, Massachusetts Institute of Technology (MIT), 2011
  • B.S., Mechanical Engineering, University of Missouri, Rolla, 2007, summa cum laude

LICENSES & CERTIFICATIONS

Licensed Professional Engineer, North Carolina, #045020

Licensed Professional Mechanical Engineer, Massachusetts, #52627

Licensed Professional Engineer, Missouri, 2018007867

Licensed Professional Engineer, Indiana, PE00800105

Hazardous Waste Operation and Emergency Response Certification, 29 CFR 1910.120

Blasting Certificate of Competency, Massachusetts, BL 7236

Certified Fire and Explosion Investigator (CFEI) in accordance with the National Association of Fire Investigators Nation Certification Board per NFPA 921 Section 13.6.5.2

Leadership in Energy and Environmental Design - Accredited Professional, 2008 

Publications

Humplik T, Lee J, O'Hern S, Laoui T, Karnik R, Wang E. Enhanced water transport and salt rejection through hydrophobic zeolite pores. Nanotechnology 2017; 28(50), November 21, 2017.

O'Hern SC, Stern MC, Ibarreta, AF, Myers TJ. Analysis of combustible dust flash fires on personal protective equipment fabrics. Proceedings of the IChemE Hazards27 Conference, Birmingham, UK, 2017. Awarded Frank Lees Medal for the most meritorious publication on the topic of safety and loss prevention in an IChemE publication.

Ibarreta AF, Myers TJ, Stern MC, O'Hern SC. Portable vacuums for AM/PM operations: The good, the bad and the ugly. Proceedings POWDERMET 2017, International Conference on Powder Metallurgy & Particulate Materials, Las Vegas, NV, 2017.

Myers TJ, Ibarreta AF, O'Hern SC. Mitigating fire and explosion hazards of metal powders: update on changing consensus standards, Proceedings POWDERMET 2016, International Conference on Powder Metallurgy & Particulate Materials, Boston, MA, 2016.

Myers TJ, Ibarreta AF, Stern MC, O'Hern SC, Page CD. Combustible dust hazards in additive manufacturing operations, Proceedings POWDERMET 2016, International Conference on Powder Metallurgy & Particulate Materials, Boston, MA, 2016.

Jain T, Rasera BC, Guerrero RJS, Boutilier MSH, O'Hern SC, Idrobo J-C, Karnik R. Heterogeneous sub-continuum ionic transport in statistically isolated graphene nanopores. Nature Nanotechnology 2015.

O'Hern SC, Jang D, Bose S, Idrobo J-C, Song Y, Laoui T, Kong J, Karnik R. Nanofiltration across defect-sealed nanoporous monolayer graphene. Nano Letters 2015.

O'Hern SC, Boutilier MSH, Idrobo J-C, Song Y, Kong J, Laoui T, Atieh M, Karnik R. Selective ionic transport through tunable subnanometer pores in single-layer graphene membranes. Nano Letters, 2014.

Boutilier MSH, Sun C, O'Hern SC, Au H, Hadjiconstantinou N, Karnik R. Implications of permeation through intrinsic defects in graphene on the design of defect-tolerant membranes for gas separation. ACS Nano, 2013.

O'Hern SC, Stewart CA, Boutilier MSH, Idrobo J-C, Bhaviripudi S, Das SK, Kong J, Laoui T, Atieh M, Karnik R. Selective Molecular transport through intrinsic defects in a single layer of CVD graphene. ACS Nano, 2012.

O'Hern SC. Development of process to transfer large areas of LPCVD graphene from copper foil to a porous support substrate. Master's thesis, Massachusetts Institute of Technology, 2011.

Humplik T, Lee J, O'Hern SC, Fellman BA, Baig MA, Hassan SF, Atieh MA, Rahman F, Laoui T, Karnik R, Wang EN. Nanostructured materials for water desalination. Nanotechnology, 2011.

Invited Lectures and Courses


Ogle R, O’Hern SC, Stern M. Dust Explosion Dynamics, Global Process on Process Safety, San Antonia, TX, 2017

Ibarreta A, O'Hern S C. Explosion Protection in Industrial Settings, Worcester Polytechnic Institute, Department of Fire Protection Engineering. April 2016.

Presentations

Stern M C, O'Hern S C, Morse T L, Bishop J, Kytomaa H. Fire risks due to unintentionally energized metal structures. 2016 International Symposium on Fire Investigation, Scottsdale, AZ, 2016.

Jang D, O'Hern S C, Kidambi P, Boutilier M S H, Song Y, Idrobo J-C, Kong J, Laoui T, Karnik R. Development of defect tolerant high-flux graphene membranes for nanofiltration. North American Membrane Society Meeting, Boston, MA, 2015.

Kidambi P, Jang D, Boutilier M S H, Wang L, O'Hern S C, Karnik R. Chemical vapor deposition of atomically thin materials for membrane and barrier applications. 2015 North American Membrane Society Meeting, Boston, MA, 2015.

Boutilier MSH, Jang D, Wang L, O'Hern S C, Kidambi P, Hadjiconstantinou N, Karnik R. Development of nanoporous membranes for gas separation. 2015 North American Membrane Society Meeting, Boston, MA, 2015.

Ibarreta A, Marr K, Garner S, O'Hern S C, Myers TJ. On the use of laminar burning velocities in process safety. Proceedings, 11th Global Congress on Process Safety, American Institute of Chemical Engineers Spring Meeting, Austin, TX, 2015.

O'Hern SC, Jang D, Boutilier MSH, Song Y, Idrobo J-C, Kong J, Atieh M, Laoui T, Karnik R. High-performance monolayer graphene membrane for nanofiltration. Materials Research Society Fall Meeting, Boston, MA, 2014.

O'Hern SC, Jang D, Boutilier MSH, Song Y, Idrobo J-C, Kong J, Atieh M, Laoui T, Karnik R. Selective ionic transport through nanoporous graphene. Flow 14 Conference, Enschede, NL, 2014.

O'Hern SC, Song Y, Boutilier MSH, Bose S, Idrobo J-C, Laoui T, Atieh M, Karnik R. Selective molecular transport through controlled pores in large-area graphene membranes. Materials Research Society Fall Meeting, Boston, MA, 2013.

O'Hern SC, Song Y, Boutilier MSH, Bose S, Idrobo J-C, Laoui T, Atieh M, Karnik R. Tuning the selectivity of graphene membranes by nucleation and growth of pore defects. ASME IMECE 2013, San Diego, CA, 2013.

O'Hern SC, Stewart CA, Boutilier MSH, Lee J, Jain T, Idrobo J-C, Laoui T, Atieh M, Karnik R. Ionic transport through intrinsic nanometer-scale pores in CVD graphene. MIT Water Night, Cambridge, MA, 2013.

O'Hern SC, Stewart CA, Boutilier MSH, Lee J, Jain T, Idrobo J-C, Laoui T, Atieh M, Karnik R. Molecular transport through porous graphene membranes. Materials Research Society Fall Meeting, Boston, MA, 2012.

O'Hern SC, Stewart CA, Boutilier MSH, Lee J, Jain T, Idrobo J-C, Bhaviripudi S, Kong J, Laoui T, Atieh M, Karnik R. Size-selective transport through intrinsic nanometer-scale pores in graphene membranes. Oak Ridge National Laboratory Shared Research Equipment Program Review, Oak Ridge, TN, 2012.

O'Hern SC, Stewart CA, Boutilier MSH, Idrobo J-C, Bhaviripudi S, Das SK, Kong J, Laoui T, Atieh M, Karnik R. Size-selective transport of molecules through nanoporous graphene membranes. ICREA Symposium 2012: Nanofluidics, Colloids, and Membranes, Barcelona, Spain, 2012.

Lee J, O'Hern SC, Rahman F, Laoui T, Karnik R. Vapor trapping membranes for water desalination. Conference and Exhibition on Desalination for the Environment: Clean Water and Energy, Barcelona, Spain, 2012.

O'Hern SC, Stewart CA, Boutilier MSH, Lee J, Jain T, Idrobo J-C, Laoui T, Atieh M, Karnik R. Characterization of graphene membranes for nanofiltration. Materials Research Society Spring Meeting, San Francisco, CA, 2012.

Lee J, O'Hern SC, Laoui T, Rahman F, Karnik R. Vapor transport through short hydrophobic nanopores for desalination. American Physical Society: Division of Fluid Dynamics, 64th Annual Meeting, Baltimore, MD, 2011.

Lee J, O'Hern SC, Karnik R, Laoui T. Vapor-trapping membrane for reverse osmosis. ASME 2010 International Mechanical Engineering Congress and Exposition (IMECE2010), Vancouver, CA, 2010.

Laoui T, Hassan SF, Karnik R, Wang E, Al-Hooshani K, Rahman F, Atieh M, Humplik T, Lee J, Fellman B, O'Hern SC, Baig M A, Patel F. Nanostructured membranes for water desalination. 7th International Membrane Science and Technology Conference/6th Conference of Aseanian Membrane Society, Sydney, AU, 2010.

Media Coverage

Chu J. Plugging up leaky graphene: New technique may enable faster, more durable water filters. MIT News, May 8, 2015.

Sterling B. Graphene water distillation. Wired.com, Mar 4, 2014.

Chandler D. How to create selective holes in graphene. MIT News, Feb 25, 2014.

Clark L. Graphene membrane forms pores to make super-strong filters. Wired UK, Oct 23, 2012.

Chu J. Tiny pores in graphene could give rise to membranes. MIT News, Oct 23, 2012.

Patents

Karnik R, Bose S, Boutilier MSH, Hadjiconstantinou N, Jain T, O’Hern SC, Laoui T, Atieh M, Jang D. Mitigating Leaks in Membranes, US Patent US9,901,879B2.

Karnik R, O’Hern SC, Boutilier MSH, Stewart CA, Au H, Hadjiconstantinou N, Laoui T, Atieh M. Graphene Based Filter, US Patent Application 13/835,173.

Prior Experience

Research Assistant, Massachusetts Institute of Technology, 2009-2014

Mechanical Engineer, Wiegmann Associates, 2007-2009

Non-Destructive Testing Intern, Honeywell FM&T, 2006

Machinist/Parts Inspector Intern, Pride Manufacturing, 2005

Professional Affiliations

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), 2017

  • Technical Committee 1.12: Moisture Management in Buildings (Provisional Corresponding Member)
  • Technical Committee 4.7: Energy Calculations (Corresponding Member)
  • Technical Committee 5.6: Control of Fire and Smoke (Provisional Corresponding Member)
  • Technical Committee 5.11: Humidifying Equipment (Provisional Corresponding Member)
  • Technical Committee 6.10: Fuels and Combustion (Provisional Corresponding Member)
  • Technical Committee 7.6: Building Energy Performance (Provisional Corresponding Member)
  • Technical Committee 7.9: Building Commissioning(Provisional Corresponding Member)
  • Technical Committee 9.9: Mission Critical Facilities, Data Centers, Technology Spaces and Electronic Equipment (Provisional Corresponding Member)

American Society of Mechanical Engineers (ASME), 2016

ASTM International, 2015

National Association of Fire Investigators, 2014

National Fire Protection Association, 2014

Knowledge

News & Events

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Mechanical Engineering, Massachusetts Institute of Technology (MIT), 2015
  • S.M., Mechanical Engineering, Massachusetts Institute of Technology (MIT), 2011
  • B.S., Mechanical Engineering, University of Missouri, Rolla, 2007, summa cum laude

LICENSES & CERTIFICATIONS

Licensed Professional Engineer, North Carolina, #045020

Licensed Professional Mechanical Engineer, Massachusetts, #52627

Licensed Professional Engineer, Missouri, 2018007867

Licensed Professional Engineer, Indiana, PE00800105

Hazardous Waste Operation and Emergency Response Certification, 29 CFR 1910.120

Blasting Certificate of Competency, Massachusetts, BL 7236

Certified Fire and Explosion Investigator (CFEI) in accordance with the National Association of Fire Investigators Nation Certification Board per NFPA 921 Section 13.6.5.2

Leadership in Energy and Environmental Design - Accredited Professional, 2008