Dr. Michael Thompson

Overview

The research interests of my group are focused around particulate and polymer processing, serving the plastics, pharmaceutical or functional foods industries.  We have vast expertise in screw extrusion, rotomolding, and spray drying. Through experiments and modelling, products, knowledge and software tools are being produced to assist these industrial sectors in controlling or developing their processes. We are particularly focused on controlling the morphology of novel material systems in order to achieve desired product specifications.

Current areas of research

• Twin-Screw Granulation Extrusion – particle design by wet, melt or dry processes for pharmaceutical, nutriceutical, crop protection, foods and detergent applications. Tailoring of particle size/shape/porosity on a continuous basis within an extruder through screw design and process layout. Current work includes developing scaling models and QbD compliant control strategies for the process as well as looking at how the machine can be better configured for the specific needs of granulation.
  
• Spray drying – encapsulating of biologically active ingredients that are highly sensitive to their ambient environment in order to create long-term storage stability, defying the need for cold chain compliance. The biomanufacturing techniques we are studying are applicable to many pharmaceutical products including vaccines, biotherapeutics and radiopharmaceutics. Current work seeks to understand the relationship between the chemical interactions, crystallization, and solidification mechanics taking place during spray drying to stabilize different enveloped and non-enveloped viral vectors in sugar, protein or amino acid matrices for suitable storage at ambient temperature over months to years in duration.
  
• Sensors and controller development for quality control – developing data-rich sensors and intelligent decision-making models for process control architecture. Through collaborations with the McMaster Advanced Control Consortium, we are looking at data-driven modelling methods to create sensors capable of monitoring complex features of a process, and develop model predictive controllers capable of decision making based on both process behaviour and economic constraints. Current studies are focused on control strategies for the pharmaceutical and polymer industries. 
  
• Composite/Bioplastics processing – Examination of interfacial and colloidal properties for conventional and nano-scale fillers within a polymer matrix of synthetic or biological origins. Understanding and modeling the relationship of morphology and end-user specification in product design.  Current studies seek to understand and improve upon our technology for creating extrusion and injection molding grade thermoplastics from lignocellulosic (forestry) waste, uses of canola protein isolate in structural plastics, and making bioelastomers from starch.
  
• Liquid-solid dispersions by extrusion – A unique technology to manufacture micron and nano-sized particles for polymers which can not normally be emulsified due to their high viscosities. The novel method uses a twin-screw extruder to emulsified a polymer. We are currently working on a ‘green’ manufacturing process to manufacture 100-200 nm latex particles without solvents, and have published our successes so far. Our interests are focused on how to scale the process and extending the technology to a wide range of polymers.

Recent research projects

1. Spray Drying Thermally Stable Vaccines

Addressing a global health challenge to increase the thermal stability of vaccines so that they may be stored and transported without the necessity of cold storage equipment is one of our main goals in this work. We are looking at the complex interactions taking place during spray drying to produce an encapsulated vaccine that retains its potency for a prolonged period, in the order of months, at elevated temperatures (ex. 20 deg. C) which would rapidly harm the biologic if stored in normal liquid form.

Select publications:

• V. Singh, M. D’Agostino, J. Ang, M. Miller, M. Dolovich, E. Cranston, M.R. Thompson. Influence of L-leucine as a dispersibility enhancer on inhalation performance and immunogenicity of a dry powder influenza vaccine. Journal of Drug Delivery Science and Technology, 112, 107220 (2025)
• M. Manser, V. Jeyanathan, M. Jeyanathan, X. Feng, M. B Dolovich, Z. Xing, E. D Cranston, M. R Thompson, Design Considerations for Intratracheal Delivery Devices to Achieve Proof-of-Concept Dry Powder Biopharmaceutical Delivery in Mice, Pharmaceutical Research, 40, 1165-1176 (2023)
• B.A. Morgan, E Niinivaara, Z. Xing, M.R. Thompson, E.D. Cranston, Validation of a diffusion-based single droplet drying model for encapsulation of a viral-vectored vaccine using an acoustic levitator, International Journal of Pharmaceutics, 605, 120806 (2021)
• S. P. Toniolo, S. Afkhami, A. Mahmood, C. Fradin, B.D. Lichty, M. S. Miller, Z. Xing, E. D. Cranston, M. R. Thompson, “Excipient selection for thermally stable enveloped and non-enveloped viral vaccine platforms in dry powders”, International Journal of Pharmaceutics, 561, 66-73 (2019)
• S. Afkhami, D.A. LeClair, S. Haddadi, R. Lai, S.P. Toniolo, H.C. Ertl, E. D. Cranston, M. R Thompson, Z. Xing*, “Spray dried human and chimpanzee adenoviral-vectored vaccines are thermally stable and immunogenic in vivo”, Vaccine 35, 2916-2924 (2017)
• D. A. LeClair, E. D. Cranston, Z. Xing, M. R. Thompson, “Enhanced Thermal Stabilization for Human Type 5 Adenoviral Vector through Spray Drying”, International Journal of Pharmaceutics, 506, 289-301 (2016)

2. Granulation Extrusion

Twin screw extrusion (TSE) is a relatively novel technology for the Pharmaceutical and Nutraceutical industries, offering continuous manufacturing capability with superior mixing of particulate matter being granulated or wetted. Our research examines:

• Foam granulation – this robust, continuous manufacturing technology using a twin screw extruder was developed by our group in collaboration with the original co-inventor (Paul Sheskey, Dow Chemical) to consider aqueous foam as a binder.
• Wet granulation – studying the influence of process, material and screw design factors on granule development, using liquid injection or foam delivery methods.
• Hydrid dry granulation – a method similar to melt granulation but minimizing the product exposure to heat.
• Melt granulation – use of a molten binder to granulate excipients without the use of water.

Experimental studies and numerical particle simulation approaches are being used to advance the integration of extrusion technology into these industries.

Select publications:

• H.A. Abdulhussain, MR Thompson, Examining Particle Size Growth in Twin Screw Granulation up to Steady State with Acoustic Emissions, Powder Technology 448, 120294 (2024)
• H.A. Abdulhussain, M.R. Thompson, Predicting the particle size distribution in twin screw granulation through acoustic emissions,Powder Technology, 394, 757-766 (2021)
• Y. Liu, M.R. Thompson*, K.P. O’Donnell, “Impact of non-binder ingredients and molecular weight of polymer binders on heat assisted twin screw dry granulation”, International Journal of Pharmaceutics, 536, 336-344 (2017).
• H Li, M.R Thompson*, K.P O’Donnell, “Examining drug hydrophobicity in continuous wet granulation within a twin screw extruder” International Journal of Pharmaceutics, 496, 3-11 (2015)
• S. Weatherley, B. Mu, P.J. Sheskey, K. P. O’Donnell, M.R. Thompson*. “Hot melt granulation in a twin screw extruder: Effects of processing on formulations with caffeine and ibuprofen”, Journal of Pharmaceutical Science, 102, 4330-4336 (2013)
• M.R. Thompson*, S. Weatherley, R.N Pukadyil, and P.J. Sheskey, “Foam Granulation: New Developments in Pharmaceutical Solid Oral Dosage Forms using Twin Screw Extrusion”, Drug Development and Industrial Pharmacy., 38, 771–784 (2012)

3. Sensors and Control Systems

We are interested in relating physical details of a process to the complex spectral data of infrared and acoustic sensors (i.e. process analytical technologies) and developing intelligent control strategies that can implement this large amount of data to make decisions that may be product or economic specific. We envision new online quality assessments to inform advanced control models which are tasked with making decision on product properties in real-time. We are focused presently on ultrasonic sensors, and control systems for rotational molding (a batch polymer process) and twin-screw granulation (a continuous pharmaceutical process).

Select publications:

• A. Bedrosian, A. Hrymak, G. Lanza, M.R. Thompson. Understanding a frequency shifting phenomenon interfering with in-line acoustic monitoring of an extrusion compounding process for polymer composites. Journal of Thermoplastic Composite Materials 38(8), 2976-2994 (2025)
• A. Chandrasekar, K. Baghdassarian, F. Moayedi, H. Abdulhussain, V. Gritsichine, M.R. Thompson, P. Mhaskar, Image based Modeling and Control for Batch Processes, Journal of Process Control 143, 103314 (2024)
• A.K. Saad, H.A. Abdulhussain, F.P.C. Gomes, J. Vlachopoulos, M.R. Thompson, Studying the mechanism of biodiesel acting as an environmental stress cracking agent with polyethylenes, Polymer, 191, 122278 (2020)
• A. Garg, F. P. C. Gomes, P. Mhaskar, M. R. Thompson, “Model Predictive Control of Uni-Axial Rotational Molding Process”, Computers and Chemical Engineering, 121, 306-316 (2019)
• F.P.C. Gomes, M. R. Thompson, “Nondestructive evaluation of sintering and degradation for rotational moulded polyethylene”, Polymer Degradation and Stability, 157, 34-43 (2018)
• M. Zaiß, M. Jank, U. Netzelmann, T. Waschkies, U. Rabe, H.-G. Herrmann, M. Thompson, G. Lanza, “Use of Thermography and Ultrasound for the Quality Control of SMC Lightweight Material Reinforced by Carbon Fiber Tapes”, Procedia CIRP, 62, 33–38 (2017)

4. Solvent Free Extrusion Emulsification

There are many polymers that cannot be grown by polymerization as an emulsion due to their water sensitivity or are naturally derived (ex. xanthan and guar gums). There is also often a desire to make an emulsion where the polymer particles contain other ingredients such as a drug, pesticide, etc. Solvent emulsification is the current route to synthesis in such cases but the solvent is costly and its recovery is expensive, many polymer exhibit limited solubility in any solvent, the precipitation process is long and the purity of the polymer product is always in question. We are working to understand a new technique where a polymer melt that was plasticized inside a twin screw extruder can be converted into nanosized (~100nm) particles suspended in an aqueous solution, never touching solvents during the process.

Select publications:

• A. Arefi, J. Pawlak, C.-M. Cheng, D. Lawton, M.R. Thompson. Understanding the influence of mixing on a solvent-free emulsification process for highly viscous polymers using a twin-screw extruder. Polymer Engineering and Science 65(3), 1311-1326 (2025)
• T. Ivancic, C. Lu, R Sheppard, M.R. Thompson, J.L. Pawlak, C.M. Cheng, D.L.W. Lawton, Investigating the Synergistic Anionic/Nonionic Surfactant Interaction on Nanoparticle Synthesis with Solvent-Free Extrusion Emulsification, ACS Industrial & Engineering Chemistry Research, 59, 9787-9796 (2020)
• A. Goger, M.R. Thompson, J.L. Pawlak, M. Arnould, D.J.W. Lawton, “Effect of Viscosity on Solvent-Free Extrusion Emulsification: Varying System Temperature”, Industrial & Engineering Chemistry Research, 57, 12071–12077 (2018)
• A. Goger, M.R. Thompson J.L. Pawlak, M.A. Arnould and D.J.W. Lawton, Solvent-free polymer emulsification inside a twin screw extruder, AICHE Journal, 64, 2113-2123 (2018)
• A. Goger, M.R. Thompson, J.L. Pawlak, M. Arnould, A. Klymachyov, “Effect of Viscosity on Solvent-Free Extrusion Emulsification: Molecular Structure”, Industrial & Engineering Chemistry Research, 56, 12538–12546 (2017)

5. Bioplastics, Foams and Reactive Modifications

We are interested in understanding the root phenomena influencing important industrial problems such as product quality and process stability which arise as special materials are being prepared by extrusion. Bioplastics are a new category of polymers which present benefits to industries where single-use applications are dominant and low mechanical strength can be tolerated, like the packaging sector. As a new material class, these bioplastics often require very different machinery configurations and processing practices be used compared to petroleum plastics. In foaming, our group is examining processing aspect of foaming by physical and chemical blowing agents and how foaming may be utilized with composite materials like thermoplastic olefin elastomers, glass-fibre reinforced thermoplastics, and nanocomposites to do more than simply reduce part weight, like control fibre orientation. In reactive modification of polymers, the polymer processing equipment is used as a solvent-less reactor to change the molecular architecture of a material. Unique chemistries are employed in this high-temperature, high pressure environment to bring about the desired change in the molecular architecture of the polymer.

Selected publications:

• S. Ogunniyi, S. Zhu, M.R. Thompson. Increasing adsorption by wood flour of quaternary ammonium salts to improve reactivity when preparing thermoplastic lignocellulose, Cellulose 32, 9333-9349 (2025)
• J. Li, H. Zhang, G.G. Sacripante, D.J.W. Lawton, H.S. Marway, M.R. Thompson, Solvent-free modification of lignocellulosic wood pulp into a melt-flowable thermoplastic, Cellulose, 28, 1055-1069 (2021)
• J. Li, M.R Thompson, D.J.W. Lawton, “Improved Chemical Reactivity of Lignocellulose from High Solids Content Micro-fibrillation by Twin-screw Extrusion”, Journal of Polymers and the Environment, 27(3), 643-651 (2019)
• S. Li, K. Ciardullo, E. Donner, M.R. Thompson, C. Rempel, Q. Liu*, “Reactive extrusion preparation and characterization of canola meal composites reinforced by a novel polymeric chain extender”, Materials & Design 138, 1-10 (2018)
• Y Du, F Chen, Y Zhang, C Rempel, MR Thompson, Q Liu*, “Potato protein isolate‐based biopolymers”, Journal of Applied Polymer Science, 132, 42723 (2015)
• G. J. He, Q. Liu*, M. R. Thompson, “Characterization of Structure and Properties of Thermoplastic Potato Starch Film Surface Cross-linked by UV Irradiation”, Starch/Starke, 65, 304-311 (2013)
• D. Chen, D. Lawton, M.R. Thompson*, Q. Liu, “Biocomposites Reinforced with Cellulose Nanocrystals derived from Potato Peel Waste”, Carbohydrate Polymers, 90, 709-716 (2012).

Education

• B.Sc. McMaster University (1990)
• B. Eng. McMaster University (1992)
• M. Eng. McMaster University (1994)
• Ph.D. University of Waterloo (1998)

Publications

Recent

• A. Morgan, E Niinivaara, Z. Xing, M.R. Thompson, E.D. Cranston, Validation of a diffusion-based single droplet drying model for encapsulation of a viral-vectored vaccine using an acoustic levitator, International Journal of Pharmaceutics, 605, 120806 (2021)
• Li, T. Baker, G.G. Sacripante, D.J.W. Lawton, H. Marway, H. Zhang, Solvent-free production of thermoplastic lignocellulose from wood pulp by reactive extrusion, Carbohydrate Polymers, 270, 118361 (2021)
• B. Kornberg, M.R. Thompson, S. Zhu, Flexible conductive substrate incorporating a submicrometer co-continuous polyaniline phase within polyethylene by controlled crazing, ACS Applied Polymer Materials, 3, 1880-1889 (2021)
• Li, H. Zhang, G.G. Sacripante, D.J.W. Lawton, H.S. Marway, M.R. Thompson, Solvent-free modification of lignocellulosic wood pulp into a melt-flowable thermoplastic, Cellulose, 28, 1055-1069 (2021)
• P. Toniolo, S. Afkhami, M.R. D’Agostino, B.D. Lichty, E.D. Cranston, Z. Xing, M.R. Thompson, Spray dried VSV-vectored vaccine is thermally stable and immunologically active in vivo, Scientific Reports, 10, 13349 (2020) [open source]
• A. Morgan, M. Manser, M. Jeyanathan, Z. Xing, E.D. Cranston, M.R. Thompson, Effect of shear stresses on adenovirus activity and aggregation during atomization to produce thermally stable vaccines by spray drying, ACS Biomaterials Science & Engineering, 6, 4304-4313 (2020)
• Kornberg, M. Thompson, S. Zhu, Developing continuous submicron-scale conductive interpenetrating hydrogel network in polyethylene matrices through controlled crazing and polymerization, Industrial & Engineering Chemistry Research, 59, 6609-6616 (2020)
• Ivancic, C. Lu, R Sheppard, M.R. Thompson, J.L. Pawlak, C.M. Cheng, D.L.W. Lawton, Investigating the Synergistic Anionic/Nonionic Surfactant Interaction on Nanoparticle Synthesis with Solvent-Free Extrusion Emulsification, ACS Industrial & Engineering Chemistry Research, 59, 9787-9796 (2020)
• Ivancic, M.R. Thompson, J.L. Pawlak, D.L.W. Lawton, Influence of Anionic and Non-Ionic Surfactants on Nanoparticle Synthesis by Solvent-Free Extrusion Emulsification, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 587, 124328 (2020)
• K. Saad, H.A. Abdulhussain, F.P.C. Gomes, J. Vlachopoulos, M.R. Thompson, Studying the mechanism of biodiesel acting as an environmental stress cracking agent with polyethylenes, Polymer, 191, 122278 (2020)
• Zhao, F.P.C. Gomes, H. Marway, M.R. Thompson, Z. Zhu, Physical Aging as the Driving Force for Brittle–Ductile Transition of Polylactic Acid, Macromolecular Chemistry and Physics, 221, 1900475 (2020)
• A. LeClair, L. Li, N. Rahman, E.D. Cranston, Z. Xing, M.R. Thompson, Stabilization of HSV-2 viral vaccine candidate by spray drying, International Journal of Pharmaceutics, 569, 118615 (2019)
• Garg, H.A. Abdulhussain, P. Mhaskar, M.R. Thompson, Handling Constraints and Raw Material Variability in Rotomolding through Data-Driven Model Predictive Control, Processes, 7, 610 (2019)
• Zhao, MR. Thompson. Z. Zhu, Effect of poly(2‐ethyl‐2‐oxazoline) and UV irradiation on the melt rheology and mechanical properties of poly(lactic acid), Journal of Applied Polymer Science, 136, 48023 (2019)
• K. Saad, F.P.C. Gomes, M.R. Thompson, Plasticizing effect of oxidized biodiesel on polyethylene observed by nondestructive method, Fuel, 252, 246-253 (2019)
• A. Morgan, Z. Xing, E.D. Cranston, M. R. Thompson, Acoustic levitation as a screening method for excipient selection in the development of dry powder vaccines, International Journal of Pharmaceutics, 563, 71-78 (2019)
• P. Toniolo, S. Afkhami, A. Mahmood, C. Fradin, B.D. Lichty, M.S. Miller, Z. Xing, E.D. Cranston, M.R. Thompson, Excipient selection for thermally stable enveloped and non-enveloped viral vaccine platforms in dry powders, International Journal of Pharmaceutics, 561, 66-73 (2019)
• Li, M.R Thompson, D.J.W. Lawton, Improved Chemical Reactivity of Lignocellulose from High Solids Content Micro-fibrillation by Twin-screw Extrusion, Journal of Polymers and the Environment, 27, 643-651 (2019)
• Schäferling, B. Häfner, G. Lanza, A. Trauth, K. Weidenmann, M. Thompson, Effects of defects in Hybrid Sheet Moulding Compound, Material Science and Engineering Technology (Materialwissenschaft und Werkstofftechnik), 50, 1317-1325 (2019)
• Ciaredullo, E. Donner, Q. Liu, M.R. Thompson, Influence of extrusion mixing on preparing lipid complexed pea starch for functional foods, Starch/Starke, 71, 1800196 (2019)
• Garg, F.P.C. Gomes, P. Mhaskar, M.R. Thompson, Model Predictive Control of Uni-Axial Rotational Molding Process, Computers and Chemical Engineering, 121, 306-316 (2019)
• Alturkestany, V. Panchal, M.R. Thompson, Improved part strength for the fused deposition 3-D printing technique by chemical modification of polylactic acid, Polymer Engineering and Science, 59 (Special Issue S2), E59-E64 (2019)
• Li, B. Ball, E. Donner, M.R. Thompson, C. Rempel, Q. Liu, Mechanical properties of green canola meal composites and reinforcement with cellulose fibers, Polymer Bulletin, 76, 1257-1275 (2019)
• P.C. Gomes, M. R. Thompson, Nondestructive evaluation of sintering and degradation for rotational molded polyethylene, Polymer Degradation and Stability, 157, 34-43 (2018)
• Goger, M.R. Thompson, J.L. Pawlak, M. Arnould, D.J.W. Lawton, Effect of Viscosity on Solvent-Free Extrusion Emulsification: Varying System Temperature, Industrial & Engineering Chemistry Research, 57, 12071–12077 (2018)
• LeClair, E.D. Cranston, B.D. Lichty, Z. Xing, M.R. Thompson, Consecutive spray drying to produce coated dry powder vaccines suitable for oral administration, ACS Biomaterials Science & Engineering, 4, 1669-1678 (2018)
• Li, K. Ciardullo, E. Donner, M.R. Thompson, C. Rempel, Q. Liu, Reactive processing preparation of sustainable composites from canola meal reinforced by chemical modification, European Polymer Journal, 102, 187-194 (2018)
• Goger, M.R. Thompson, J.L. Pawlak, M.A. Arnould and D.J.W. Lawton, Solvent-free polymer emulsification inside a twin screw extruder, AICHE Journal, 64, 2113–2123 (2018)
• Li, K. Ciardullo, E. Donner, M.R. Thompson, C. Rempel, Q. Liu, Reactive extrusion preparation and characterization of canola meal composites reinforced by a novel polymeric chain extender, Materials & Design, 138, 1-10 (2018)
• Goger, M.R. Thompson, J.L. Pawlak, M.A. Arnould, A. Klymachyov, R. Sheppard, D.J.W. Lawton, Inline rheological behavior of dispersed water in a polyester matrix with a twin screw extruder, Polymer Engineering & Science, 58, 775-783 (2018)

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