2022–Present
Research Area Specialist Senior and Lecturer
University of Michigan, Ann Arbor, Michigan
Career
Positions held
2021–2022
Postdoctoral Scholar
Northern Arizona University, Flagstaff, Arizona
2019–2021
Postdoctoral Research Associate
Massachusetts Institute of Technology, Cambridge, Massachusetts
2016–2018
Lecturer
University of Pennsylvania, Philadelphia, Pennsylvania
Academic background
Education
2016
Ph.D. in Mechanical Engineering
Columbia University, New York, New York
2009
B.S. in Mechanical Engineering
Johns Hopkins University, Baltimore, Maryland
Selected projects
Research experience
Work spanning exoskeletons, assistive robotics, human factors, biomechanics, vehicle simulation, and the control of electromechanical systems.
General Research Support — University of Michigan, 2022–Present
Operated and developed the departmental machine-shop training program. Supported projects including ultrasound control of exoskeletons, passive upper-limb exoskeletons, the impact of motor performance and human trust in automated ground vehicles, and applications in virtual environments.
Powered Ankle and Hip Exoskeleton — Northern Arizona University, 2021–2022
Developed hardware and control systems for an exoskeleton with active ankle and hip joints for clinical populations. The work focused on coordinating control across multiple exoskeleton joints in support of human locomotion.
Powered Ankle Exoskeleton — Massachusetts Institute of Technology, 2019–2021
Developed hardware and control systems for an ankle exoskeleton designed to improve human performance. Created a fluent system that works with the user and adapts to different environments and tasks.
Powered Torso Exoskeleton (ROSE) — Columbia University, 2013–2016
Designed and fabricated a powered torso exoskeleton for correcting abnormal spinal curvature. Conducted experimental validation and collected biomechanical data, including EMG and kinematics.
Powered Lower-Limb Exoskeleton — University of Delaware and Columbia University, 2009–2016
Designed and fabricated lower-limb powered exoskeletons, including ALEX II and ALEX III. Developed high- and low-level controllers and collected biomechanical data, including EMG and kinematics.
Mining Robotics — National Robotics Engineering Center, 2008–2009
Developed high-degree-of-freedom robotic vehicles and fabricated electromechanical systems for harsh and hazardous environments.
Vehicle Dynamic Simulation — National Robotics Engineering Center, 2007
Simulated vehicle dynamics using commercial packages and designed suspension-system control algorithms for use in simulation.
Instruction and mentorship
Teaching experience
Lecturer
Teaches human factors with laboratory coverage of environmental, physical, and cognitive human factors. Developed lectures and labs for a new course and teaches evaluation and design of work environments for safe, effective, and efficient work.
Lecturer
Taught introductory SolidWorks, mechatronics, and laboratory courses on dynamics, thermodynamics, heat transfer, vibrations, fluids, and structures. Advised senior design teams and Penn Aerospace's Rocketry Team.
Teaching Machine Design
Taught forward and inverse kinematics, linkages, actuation, failure analysis, and part selection. Designed laboratory equipment and projects involving gait trainers, surgical trainers, and warehouse robots.
Teaching Skills Relevant to Kayaking and Outdoor Competence
Provided instruction in river navigation, safety, paddling, rolling skills, and instructor training, using individual learning styles to develop students from novice to advanced levels.
Recognition
Professional development and honors
Kaufman Teaching Certificate
Massachusetts Institute of Technology
Anti-Violence Advocate
University of Pennsylvania
Best Paper Award — Honorable Mention
ASME International Design Engineering Technical Conferences
Departmental Fellowship
University of Delaware
General and Departmental Honors
Johns Hopkins University
Pi Tau Sigma
Mechanical Engineering Honor Society
Scholarship
Publications
Peer-reviewed journal articles and international conference proceedings concerning exoskeletons, rehabilitation robotics, biomechanics, human factors, and human–robot interaction.
- J. R. Williams, C. E. Cuddeback, S. Fang, D. Colley, N. Enlow, P. Cox, P. Pridham, and Z. E. Lerner. “OpenExo: An open-source modular exoskeleton to augment human function.” Science Robotics, vol. 10, no. 103, 2025: eadt1591.
- M. I. Wu, P. Stegall, H. C. Siu, and L. Stirling. “Impact of haptic cues and an active ankle exoskeleton on gait characteristics.” Human Factors, vol. 66, no. 3, pp. 904–915, 2024.
- G. Nguyen, A. Stankovic, R. Bellisle, J. Todd, R. Browder, P. Pridham, and K. Arquilla. “Examining relationships between behavior, social environment, and trait factors on mood and anxiety state during social isolation and pseudo-confinement.” Acta Astronautica, 2023.
- P. Pridham and L. Stirling. “Ankle exoskeleton torque controllers based on soleus muscle models.” PLoS ONE, vol. 18, no. 2, 2023.
- S. Gonzalez, P. Stegall, S. M. Cain, H. C. Siu, L. Stirling. “Assessment of a powered ankle exoskeleton on human stability and balance.” Applied Ergonomics, 2022.
- S. Gonzalez, P. Stegall, H. Edwards, L. Stirling, and H. C. Siu. “Ablation analysis to select wearable sensors for classifying standing, walking, and running.” Sensors, vol. 21, no. 1, p. 194, 2021.
- J. H. Park, P. Stegall, D. P. Roye, and S. K. Agrawal. “Robotic Spine Exoskeleton (RoSE): Characterizing the three-dimensional stiffness of the human torso in the treatment of spine deformity.” Neural Systems and Rehabilitation Engineering, IEEE Transactions on, 2018.
- P. Stegall, D. Zanotto, and S. K. Agrawal. “Variable Damping Force Tunnel for Gait Training Using ALEX III.” Robotics and Automation Letters, IEEE, vol. 2, no. 3, pp. 1495–1501, 2017.
- J. H. Park, P. Stegall, H. Zhang, and S. K. Agrawal. “Walking with a backpack using load distribution and dynamic load compensation reduces metabolic cost and adaptations to loads.” IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 25, no. 9, pp. 1419–1430, 2016.
- J. H. Park, P. Stegall, and S. K. Agrawal. “Reducing dynamic loads from a backpack during load carriage using an upper body assistive device.” Mechanisms and Robotics, ASME Journal of, vol. 8, no. 5, 2016.
- D. Zanotto, Y. Akiyama, P. Stegall, and S. K. Agrawal. “Knee joint misalignment in exoskeletons for the lower extremities: Effects on user's gait.” Robotics, IEEE Transactions on, vol. 31, no. 4, pp. 978–987, 2015.
- S. Srivastava, P.-C. Kao, S. Kim, P. Stegall, D. Zanotto, J. Higginson, S. Agrawal, and J. Scholz. “Assist-as-needed robot-aided gait training improves walking function in individuals following stroke.” IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 23, pp. 956–963, 2015.
- P. Stegall, K. Winfree, D. Zanotto, and S. K. Agrawal. “Rehabilitation exoskeleton design: Exploring the effect of the anterior lunge degree of freedom.” Robotics, IEEE Transactions on, vol. 29, no. 4, pp. 838–846, 2013.
- D. Zanotto, G. Rosati, S. Spagnol, P. Stegall, and S. K. Agrawal. “Effects of complementary auditory feedback in robot-assisted lower extremity motor adaptation.” Neural Systems and Rehabilitation Engineering, IEEE Transactions on, vol. 21, no. 5, pp. 775–786, 2013.
- D. W. Han, S. Bhat, S. Yang, J. Smith, A. Salour, T. Stroup, P. Pridham, Y. Liu, and X. J. Yang. “Interactions Between Workers and Automated Guided Vehicles: Impact of eHMI Design.” Proceedings of the Human Factors and Ergonomics Society Annual Meeting, vol. 69, no. 1, pp. 1166–1172, 2025.
- S. Yang, S. Bhat, Y. Ren, P. Pridham, X. J. Yang, T. Stroup, and A. Salour. “Identifying Worker Motion Through a Manufacturing Plant: A Finite Automaton Model.” IEEE International Conference on Robot and Human Interactive Communication, pp. 1970–1977, 2024.
- S. Bagchi et al. “Towards Improved Replicability of Human Studies in Human-Robot Interaction: Recommendations for Formalized Reporting.” ACM/IEEE International Conference on Human-Robot Interaction, 2023.
- J. Sloboda, P. Stegall, R. J. McKindles, L. Stirling, and H. C. Siu. “Utility of Inter-subject Transfer Learning for Wearable-Sensor-Based Joint Torque Prediction Models.” IEEE Engineering in Medicine and Biology Society Conference, pp. 4901–4907, 2021.
- E. J. Park, J. Kang, H. Su, P. Stegall, D. L. Miranda, W. Hsu, M. Karabas, N. Phipps, S. K. Agrawal, E. C. Goldfield, and C. J. Walsh. “Design and preliminary evaluation of a multi-robotic system with pelvic and hip assistance for pediatric gait rehabilitation.” IEEE International Conference on Rehabilitation Robotics, pp. 332–339, 2017.
- J. H. Park, P. Stegall, S. K. Agrawal, S. Yarlagadda, J. Tierney, S. Sharma, and J. Gillespie. “Wearable Upper Body Suit for Assisting Human Load Carriage.” International Design Engineering Technical Conferences, ASME, 2015. Best Paper Award Honorable Mention
- Z. Sheng, J. H. Park, P. Stegall, and S. K. Agrawal. “Analytic Determination of Wrench Closure Workspace of Spatial Cable Driven Parallel Mechanisms.” International Design Engineering Technical Conferences, ASME, 2015.
- J. H. Park, P. Stegall, and S. K. Agrawal. “Dynamic brace for correction of abnormal postures of the human spine.” IEEE International Conference on Rehabilitation Robotics, pp. 5922–5927, 2015.
- J. H. Park, D. Zanotto, V. Vashista, X. Jin, P. Stegall, and S. K. Agrawal. “Second spine: A device to relieve stresses on the upper body during loaded walking.” IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, pp. 689–694, 2014.
- V. Youssofzadeh, D. Zanotto, P. Stegall, M. Naeem, K. Wong-Lin, S. K. Agrawal, and G. Prasad. “Directed neural connectivity changes in robot-assisted gait training: A partial granger causality analysis.” Engineering in Medicine and Biology Society Conference, pp. 6361–6364, 2014.
- D. Zanotto, P. Stegall, and S. K. Agrawal. “Adaptive assist-as-needed controller to improve gait symmetry in robot-assisted gait training.” IEEE International Conference on Robotics and Automation, pp. 724–729, 2014.
- J. H. Park, P. Stegall, D. Zanotto, V. Vashista, X. Jin, and S. K. Agrawal. “Design of the second spine: A secondary pathway to transfer loads from the shoulders to the pelvis.” ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, 2013.
- D. Zanotto, T. Lenzi, P. Stegall, and S. K. Agrawal. “Improving transparency of powered exoskeletons using force/torque sensors on the supporting cuffs.” IEEE International Conference on Rehabilitation Robotics, pp. 1–6, 2013.
- D. Zanotto, P. Stegall, and S. K. Agrawal. “Alex III: A novel robotic platform with 12 DOFs for human gait training.” IEEE International Conference on Rehabilitation Robotics, pp. 3914–3919, 2013.
- T. Lenzi, D. Zanotto, P. Stegall, M. Carrozza, and S. K. Agrawal. “Reducing muscle effort in walking through powered exoskeletons.” IEEE Engineering in Medicine and Biology Society Conference, pp. 3926–3929, 2012.
- P. Stegall, K. N. Winfree, and S. K. Agrawal. “Degrees-of-freedom of a robotic exoskeleton and human adaptation to new gait templates.” IEEE International Conference on Robotics and Automation, pp. 4986–4991, 2012.
- D. Zanotto, G. Rosati, F. Avanzini, P. Stegall, and S. K. Agrawal. “Robot-assisted gait training with complementary auditory feedback: Results on short-term motor adaptation.” IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, pp. 1388–1393, 2012.
- K. N. Winfree, P. Stegall, and S. K. Agrawal. “Design of a minimally constraining, passively supported gait training exoskeleton: ALEX II.” IEEE International Conference on Rehabilitation Robotics, pp. 1–6, 2011.
Innovation
Patents
Spinal treatment device, methods, and systems
S. K. Agrawal, J. H. Park, P. Stegall
US Patent US10639185B2
Active movement training devices, methods, and systems
S. K. Agrawal, D. Zanotto, P. Stegall
US Patent US9662526B2
Powered orthosis systems and methods
S. K. Agrawal, K. N. Winfree, P. Stegall, J. P. Scholz
US Patent US8771208B2
Back Brace
C. J. Kim, J. Ring, J. Nijssen, S. Pratt, S. Agrawal,
P. Stegall, J. Park
US Patent Application US20180042755A1
Back Brace
C. J. Kim, J. Ring, J. Nijssen, S. Pratt, S. Agrawal,
P. Stegall, J. Park
WO Patent Application WO2018035132A1
Technical capabilities
Skills
Computer and control
Fabrication
Biomedical engineering
Professional engagement
Service and reviewing
- IOE Facilities and Computing Committee, University of Michigan (2024–Present)
- IOE Community Engagement Committee, University of Michigan (2023–Present)
- IOE Safety Committee, University of Michigan (2022–Present)
- IOE Renovation Committee, University of Michigan (2023–2025)
- IEEE P3018 Recommended Practice for Human-Robot Interaction Design of Human Subject Studies
- IEEE P3107 Standard Terminology for Human-Robot Interaction
- Aeronautics and Astronautics Diversity, Inclusion, and Innovation Committee
- Researcher and Postdoctoral Association of Aeronautics and Astronautics, Funding/Innovation Chair
- Invited speaker, Launch X (2018 and 2020)
- Faculty advisor, Penn Aerospace Club Rocket Team
- Faculty advisor for senior design teams
- Supervised undergraduate research
- IEEE/ASME Transactions on Mechatronics reviewer
- IEEE Transactions on Neural Systems and Rehabilitation Engineering reviewer
- IEEE Transactions on Robotics reviewer
- IEEE Robotics and Automation Letters reviewer
- ASME Journal of Mechanisms and Robotics reviewer
- MDPI Sensors reviewer
- IEEE International Conference on Robotics and Automation reviewer
- IEEE International Conference on Rehabilitation Robotics reviewer
- IEEE Engineering in Medicine and Biology Society Conference reviewer
- IEEE International Conference on Biomedical Robotics and Biomechatronics reviewer
- ASME International Design Engineering Technical Conferences reviewer
Contact
Research, teaching, and collaboration
For inquiries related to ergonomics, assistive technology, rehabilitation engineering, exoskeletons, human factors, or academic collaboration, use the contact information provided here.