About

Sameh Tawfick is a Professor of Mechanical Science and Engineering at the University of Illinois, with a background that includes a Ph.D. from the University of Michigan obtained in 2012, and earlier degrees from Cairo University in Egypt. His academic positions include being a Professor at Illinois since August 2024, with previous roles as an Associate Professor and Assistant Professor at the same institution, and a visiting professorship at the University of Cambridge. Tawfick's research interests encompass actuators and robotic mechanisms, carbon nanomaterials such as carbon nanotubes and graphene, additive manufacturing of polymeric and composite materials, data-driven manufacturing and machine learning, nanomechanics and nanomanufacturing, as well as solid mechanics and materials. His work involves developing innovative solutions in these areas, contributing to the advancement of manufacturing, materials science, and robotics.

Research topics

• Computer Science
• Simulation
• Artificial Intelligence
• Physics
• Mechanical engineering
• Engineering
• Emergency medicine
• Mechanics
• Nanotechnology
• Materials science
• Structural engineering
• Geology
• Anesthesia
• Medical emergency
• Medicine

Selected publications

• Embedded Direct Ink Writing of Thermoset and Elastomeric Polymers via Frontal Polymerization

  arXiv (Cornell University) · 2026-05-09

  preprintOpen access

  Direct ink writing (DIW) using frontal ring-opening metathesis polymerization (FROMP) offers a compelling route to the rapid and energy-efficient fabrication of thermoset and elastomeric polymer architectures, leveraging a self-propagating exothermic curing reaction. While FP-DIW excels at freestanding path printing due to the rapid solidification, it is constrained by stringent rheological requirements, a lower bound on achievable feature size due to quenching, and the need for the reaction front to closely follow the nozzle during printing. Here, we overcome these constraints by leveraging embedded 3D printing to implement FP-DIW with delayed solidification, thereby decoupling shape retention and solidification from ink chemistry and rheology. The use of a yield-stress support medium enables extrusion of low-viscosity inks by suppressing gravitational and capillary instabilities, mitigating front quenching at small diameters, and allowing time-delayed solidification to fuse complex, overlapping, and mechanically interlinked features after deposition. Two complementary thermal initiation strategies are introduced:\ volumetric dielectric heating via microwaves and surface heating at the boundary of the support bath. Formulations based on dicyclopentadiene (DCPD), cyclooctadiene (COD), and mixtures thereof, result in tunable final mechanical properties with glass transition temperatures spanning $-50$ to $160 $$^\text{o}$C. The versatility of this approach is demonstrated through the fabrication of lattices, springs, mechanically interlocked, and multimaterial architectures. Compared to printing in air, this embedded approach introduces a substantially broader range of possible formulations, material properties, feature sizes, and architectures.

  PublisherDOI

• Hierarchical Artificial Muscle with Nonlinear Elasticity for Antagonistic and Cyclic Robotics

  Advanced Science · 2026-03-19

  articleOpen accessSenior author

  A key design motif of skeletal muscles is their arrangement in pairs to enable the cyclic, contra-lateral contractions necessary for motion. This mechanism may initially appear inefficient, since the contraction of a muscle group stretches the antagonist, increasing resistance and energy consumption. However, the hierarchical architecture of muscles provides a clever solution. By giving rise to J-shaped stress-strain responses, muscle tissue is soft at small strains, thus minimizing resistance, while it stiffens at large strains to enable economical energy release and prevent excessive elongation and damage. Here, we develop hierarchical supercoiled artificial muscles by plying fishing line fibers that recapitulate this behavior and thus allow antagonistic actuation. Computational models based on Cosserat rods reveal the physical mechanisms underlying the observed J-shaped responses. The artificial muscles are used in an antagonistic biceps/triceps arm mechanism and a vertical rope-climbing robot that weighs 14.4 grams and carries a payload 14.6 times heavier than its own weight.

  PublisherDOI

• Entanglement-Dominated Thermosets Enable High Performance with High-Fidelity Regeneration

  ChemRxiv · 2026-04-29

  article

  Thermoset plastics underpin structural materials, electronics, and transportation, yet their permanent covalent networks make recycling difficult.1–5 Existing recycling strategies for high‑Tg engineering applications that incorporate exchangeable6–15 or cleavable bonds16–20 often compromise stiffness, creep resistance, or thermal stability, and typically treat covalent junctions as the primary load-bearing elements.21,22 Rather than considering recycling as the recovery of degraded networks, here we construct thermosets in which high mechanical performance arises predominantly from dense chain entanglements, while only a sparse fraction of trigger-cleavable junctions preserves network connectivity. Long, rigid, entangled polyolefin backbones generated by frontal polymerization form high-Tg, glassy polymers with high stiffness, high toughness, and excellent creep suppression, yet fully deconstruct to soluble, linear oligomers. Programming oligomer length and end-group chemistry enables their reuse as re-entangling building blocks that regenerate thermosets with generation-invariant thermomechanical properties, including in high-temperature fiber reinforced composite matrices and additively manufactured structures. By demonstrating that load-bearing in high‑Tg engineering thermosets can be delivered primarily by entangled strands while sparse cleavable junctions preserve connectivity, this strategy maintains network topology across generations and establishes an entanglement-dominated design principle for regenerable, high-performance networks based on entanglement-dominated architectures.

  PublisherDOI

• Mechanical response and energy absorption of architected granular media

  International Journal of Mechanical Sciences · 2026-03-17

  articleOpen access

  • Introduce architected granular media (AGMs) as new energy absorbing composites. • AGMs can increase energy absorption by approximately 700% over the empty lattice. • AGM mechanical response depends on lattice geometry and granular media parameters. • Propose a mechanical interpretation of constituent interactions during AGM compression. • Hybrid AGMs can be designed to exhibit unnatural deformation modes and fracture. Both architected materials and granular media have been independently shown to significantly improve mechanical energy absorption by intentionally leveraging different energy dissipation mechanisms. Yet it is almost completely unknown how these two classes of materials can be combined to beneficially interact under compression to failure. Herein, we propose the concept of “architected granular media”, or AGMs, where an architected lattice is filled with granular media and show their combination can increase specific energy absorption up to 80% over the empty lattice. We experimentally characterize the quasi-static stress-strain compressional response to failure of auxetic and non-auxetic AGMs filled with different types of granular media, supported by image analysis, flowability measurements, and micro-CT. Results show that the auxetic AGMs preferentially activate the embedded granular media to increase specific energy absorption, and the embedded granular media properties dictate failure modes and stress-strain response. Finally, we show that patterned AGMs, where different granular media are filled in different portions of the lattice, can control failure in a predictable way, opening the possibility of engineered failure with AGMs. This paper demonstrates AGMs are promising for certain energy absorbing applications and could improve critical protective devices such as wave shielding, mechanical impact and crashworthiness, aerospace materials, and sports gear.

  PublisherDOI

• Trade-off between curing energy and rate in incremental composite manufacturing by frontal polymerization

  Composites Part A Applied Science and Manufacturing · 2026-04-13

  articleOpen accessSenior authorCorresponding

  • Energy-time-efficient incremental curing of CFRP composites is achieved via FP. • Trade-off between curing energy and rate is analytically and numerically investigated. • Manufacturing parameters from the Pareto front are experimentally validated. • A normalized areal processing rate of 59.0 h −1 demonstrates scalable manufacturing. Manufacturing large carbon fiber-reinforced polymer (CFRP) composite structures requires autoclaves that accommodate bulky volumes. The large volume and modest heating rates lead to inefficient power use and manufacturing time to achieve fully cured thermoset composites. In this study, the trade-off between curing energy and curing cycle time is numerically studied and experimentally validated for a frontal polymerization (FP)-based CFRP manufacturing process. To produce high-quality CFRP, the exothermic FP is thermally triggered using a heated tooling plate, enabling through-thickness FP under normal compaction pressure. To progressively cure large areas, the cured CFRP is translated after each curing step until the large composite part is fully processed. Computational modeling is first employed to study the trade-off relationship between the heating energy and curing time, and to identify the Pareto front for the lowest energy and highest cure rate. In addition, thermal cycle of the incremental curing process is further adjusted to reduce energy input and curing time. Incrementally cured CFRP composites achieve full cure at a normalized areal processing rate of 59.0 h −1 , with a high fiber volume fraction ( ϕ = 0.63 ) and a glass transition temperature ( T g = 166 °C). These results demonstrate the potential for rapid, scalable, and energy-saving manufacturing of large composite structures.

  PublisherDOI

• Additive Manufacturing of Continuous Carbon Fiber Thermoset Composites Based on Frontal Polymerization

  2026-01-01

  book-chapter
  PublisherDOI

• Embedded Direct Ink Writing of Thermoset and Elastomeric Polymers via Frontal Polymerization

  ArXiv.org · 2026-05-09

  articleOpen access

  Direct ink writing (DIW) using frontal ring-opening metathesis polymerization (FROMP) offers a compelling route to the rapid and energy-efficient fabrication of thermoset and elastomeric polymer architectures, leveraging a self-propagating exothermic curing reaction. While FP-DIW excels at freestanding path printing due to the rapid solidification, it is constrained by stringent rheological requirements, a lower bound on achievable feature size due to quenching, and the need for the reaction front to closely follow the nozzle during printing. Here, we overcome these constraints by leveraging embedded 3D printing to implement FP-DIW with delayed solidification, thereby decoupling shape retention and solidification from ink chemistry and rheology. The use of a yield-stress support medium enables extrusion of low-viscosity inks by suppressing gravitational and capillary instabilities, mitigating front quenching at small diameters, and allowing time-delayed solidification to fuse complex, overlapping, and mechanically interlinked features after deposition. Two complementary thermal initiation strategies are introduced:\ volumetric dielectric heating via microwaves and surface heating at the boundary of the support bath. Formulations based on dicyclopentadiene (DCPD), cyclooctadiene (COD), and mixtures thereof, result in tunable final mechanical properties with glass transition temperatures spanning $-50$ to $160 $$^\text{o}$C. The versatility of this approach is demonstrated through the fabrication of lattices, springs, mechanically interlocked, and multimaterial architectures. Compared to printing in air, this embedded approach introduces a substantially broader range of possible formulations, material properties, feature sizes, and architectures.

  PublisherOA PDF

• Improving energy conversion efficiency of ion-driven artificial muscles based on carbon nanotube yarn

  Journal of Power Sources · 2025-05-06 · 5 citations

  article
  PublisherDOI

• Fast 3D printing of fine, continuous, and soft fibers via embedded solvent exchange

  Nature Communications · 2025-01-20 · 18 citations

  articleOpen accessSenior author

  Nature uses fibrous structures for sensing and structural functions as observed in hairs, whiskers, stereocilia, spider silks, and hagfish slime thread skeins. Here, we demonstrate multi-nozzle printing of 3D hair arrays having freeform trajectories at a very high rate, with fiber diameters as fine as 1.5 µm, continuous lengths reaching tens of centimeters, and a wide range of materials with elastic moduli from 5 MPa to 3500 MPa. This is achieved via 3D printing by rapid solvent exchange in high yield stress micro granular gel, leading to radial solidification of the extruded polymer filament at a rate of 2.33 μm/s. This process extrudes filaments at 5 mm/s, which is 500,000 times faster than meniscus printing owing to the rapid solidification which prevents capillarity-induced fiber breakage. This study demonstrates the potential of 3D printing by rapid solvent exchange as a fast and scalable process for replicating natural fibrous structures for use in biomimetic functions. Soft hair arrays anchored to a substrate are useful for bio-inspired engineering applications. Here, the authors demonstrate a rapid 3D printing technique for creating fine, continuous, biomimetic hair arrays using solvent exchange. Fibers as small as 1.5 µm are printed at high speeds, offering scalability for biomimetic and structural applications.

  PublisherOA PDFDOI

• The critical plastocapillary number for a Newtonian liquid filament embedded into a viscoplastic fluid

  Journal of Non-Newtonian Fluid Mechanics · 2025-06-11 · 4 citations

  article
  PublisherDOI

Recent grants

• Carbon Nanotube Textile Fabrication by Programmable Self-Assembly

  NSF · $300k · 2018–2023

Frequent coauthors

• A. John Hart

  93 shared

• Michaël De Volder

  University of Cambridge

  87 shared

• Kaihao Zhang

  University of Illinois Urbana-Champaign

  43 shared

• Mitisha Surana

  University of Illinois Urbana-Champaign

  38 shared

• Sei Jin Park

  34 shared

• Alexander F. Vakakis

  University of Illinois Urbana-Champaign

  23 shared

• Darren Adams

  21 shared

• Elif Ertekin

  University of Illinois Urbana-Champaign

  20 shared

Education

• Doctor of Philosophy, Mechanical Engineering

  University of Michigan

  2012

Awards & honors

• Ralph A. Andersen Faculty Scholar