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Zilin Dai
Logo M.E. student in Computational Science & Engineering at Harvard University

I am a master's student in Computational Science and Engineering at Harvard University, supported by the Amazon Robotics Day One Fellowship, and I am doing my master's thesis with Prof. Debora Marks at Harvard Medical School.

My research is in AI for science, especially generative models for molecular design in biology. I currently build foundation-model-based methods to design RNA that binds target proteins. Before that, I pretrained protein language models for antibody discovery at Pfizer. Earlier, I worked on world models for robotics, computer vision, and soft robotics at Harvard, CMU, and WPI.

I am applying to Ph.D. programs for Fall 2027.

Curriculum Vitae

Education
  • Harvard University
    Harvard University
    M.E. in Computational Science & Engineering
    Amazon Day One Fellow
    Aug. 2025 - May 2027
  • Worcester Polytechnic Institute
    Worcester Polytechnic Institute
    B.S. in Computer Science
    Aug. 2021 - May 2025
Experience
  • Harvard Medical School, Marks Lab
    Harvard Medical School, Marks Lab
    Master's Thesis Student (Prof. Debora Marks)
    Sep. 2026 - present
  • Amazon
    Amazon
    Robotic Data Science Intern
    May 2026 - present
  • Harvard University
    Harvard University
    Research Student (Prof. Yilun Du)
    Jan. 2026 - Sep. 2026
  • Pfizer, AI for Drug Discovery
    Pfizer, AI for Drug Discovery
    Intern (Jun. - Dec. 2025)
    Co-op (Sep. - Dec. 2024)
    2024 - 2025
  • Carnegie Mellon University, Robotics Institute
    Carnegie Mellon University, Robotics Institute
    Research Assistant (Prof. Howie Choset)
    Jul. 2024 - Sep. 2024
  • Beth Israel Deaconess Medical Center
    Beth Israel Deaconess Medical Center
    Research Student (Prof. Feng Tian)
    Sep. 2023 - May 2024
  • Worcester Polytechnic Institute
    Worcester Polytechnic Institute
    Research Assistant (Profs. Ziming Zhang,
    Markus Nemitz, Jacob Whitehill)
    May 2022 - Jun. 2024
  • Olympus Corporation of the Americas
    Olympus Corporation of the Americas
    R&D Co-op
    Jan. 2023 - Jul. 2023
Honors & Awards
  • Amazon Fulfillment Technologies & Robotics Day One Fellowship
    Sep. 2025
  • WPI Presidential Scholarship (full four years)
    2021 - 2025
  • MIT Math Prize for Girls
    Oct. 2021
  • American Mathematics Competition, National Top 5%
    Jan. 2021
News
2026
🔥 Released The Missing Primitive, a study that diagnoses and repairs mathematical reasoning in LLMs. Check out the paper!
Oct
🧬 Started my master's thesis with Prof. Debora Marks at Harvard Medical School, working on protein-conditioned RNA design.
Sep
🎉 Our paper on frozen language anchors for noisy domain generalization was accepted to ECCV E.T. 2026.
Aug
🎉 DeformX was accepted to IROS 2026.
Jun
🎉 WireSeg-32K was accepted to the Synthetic Data for Computer Vision Workshop @ CVPR 2026.
Jun
💼 Joined Amazon as a Robotic Data Science Intern.
May
🤖 Started research on compositional world models with Prof. Yilun Du at Harvard.
Jan
2025
🎓 Started my master's in Computational Science & Engineering at Harvard, supported by the Amazon Robotics Day One Fellowship.
Sep
📄 Presented From Flat to Form-Fitting at IEEE CASE 2025.
Aug
💊 Joined Pfizer as an AI for Drug Discovery Intern, pretraining protein language models.
Jun
🎓 Graduated from WPI with a B.S. in Computer Science.
May
2024
🎤 Gave an oral presentation of our vision-based FDM printing paper at IEEE RoboSoft 2024.
Apr
Selected Publications (view all )
The Missing Primitive: Diagnosing and Repairing Mathematical Reasoning in Large Language Models
The Missing Primitive: Diagnosing and Repairing Mathematical Reasoning in Large Language Models

Shuo Xing*, Zilin Dai*, Chengyuan Qian, Fangzhou Lin, Wenjing Chen, Ping He, Pan Lu, Alvaro Velasquez, Mohit Bansal, Zhengzhong Tu (* equal contribution)

arXiv preprint 2026

We take a first step toward systematically studying mathematical understanding in LLMs. We introduce the notion of Mathematical Primitive to probe structural mathematical understanding and propose Prim, a benchmark that evaluates mathematical reasoning along four dimensions: Discovery, Generation, Digestion, and Execution. Our diagnosis shows that solution accuracy masks distinct capability profiles and that Discovery is the dominant bottleneck. Building on these findings, we introduce Absorb, a primitive-privileged self-distillation framework that consistently improves mathematical reasoning across model scales and challenging benchmarks.

The Missing Primitive: Diagnosing and Repairing Mathematical Reasoning in Large Language Models

Shuo Xing*, Zilin Dai*, Chengyuan Qian, Fangzhou Lin, Wenjing Chen, Ping He, Pan Lu, Alvaro Velasquez, Mohit Bansal, Zhengzhong Tu (* equal contribution)

arXiv preprint 2026

We take a first step toward systematically studying mathematical understanding in LLMs. We introduce the notion of Mathematical Primitive to probe structural mathematical understanding and propose Prim, a benchmark that evaluates mathematical reasoning along four dimensions: Discovery, Generation, Digestion, and Execution. Our diagnosis shows that solution accuracy masks distinct capability profiles and that Discovery is the dominant bottleneck. Building on these findings, we introduce Absorb, a primitive-privileged self-distillation framework that consistently improves mathematical reasoning across model scales and challenging benchmarks.

AdaptFuse: Training-Free Sequential Preference Inference via Externalized Bayesian Computation
AdaptFuse: Training-Free Sequential Preference Inference via Externalized Bayesian Computation

Fangzhou Lin*, Zilin Dai*, Shuo Xing, Peiran Li, Siyuan Yang, Qianwen Ge, Kazunori Yamada, Yang Zhou, Ziming Zhang, Haichong Zhang, Zhengzhong Tu (* equal contribution)

arXiv preprint 2026

LLMs struggle to accumulate evidence across multiple rounds of user interaction in a manner consistent with Bayesian inference. We propose AdaptFuse, a training-free framework that externalizes probabilistic computation from the LLM: a symbolic module maintains a Bayesian posterior over a discrete hypothesis set, while a frozen LLM contributes semantic reasoning via multi-sample Dirichlet aggregation, and the two are combined through entropy-adaptive fusion. Across flight recommendation, hotel recommendation, and web shopping, AdaptFuse consistently outperforms both prompting baselines and fine-tuned Bayesian Teaching models, without storing or training on sensitive user data.

AdaptFuse: Training-Free Sequential Preference Inference via Externalized Bayesian Computation

Fangzhou Lin*, Zilin Dai*, Shuo Xing, Peiran Li, Siyuan Yang, Qianwen Ge, Kazunori Yamada, Yang Zhou, Ziming Zhang, Haichong Zhang, Zhengzhong Tu (* equal contribution)

arXiv preprint 2026

LLMs struggle to accumulate evidence across multiple rounds of user interaction in a manner consistent with Bayesian inference. We propose AdaptFuse, a training-free framework that externalizes probabilistic computation from the LLM: a symbolic module maintains a Bayesian posterior over a discrete hypothesis set, while a frozen LLM contributes semantic reasoning via multi-sample Dirichlet aggregation, and the two are combined through entropy-adaptive fusion. Across flight recommendation, hotel recommendation, and web shopping, AdaptFuse consistently outperforms both prompting baselines and fine-tuned Bayesian Teaching models, without storing or training on sensitive user data.

Frozen Language Anchors as Noise-Robust Priors for Domain Generalization under Label Noise: An Empirical Study
Frozen Language Anchors as Noise-Robust Priors for Domain Generalization under Label Noise: An Empirical Study

Zilin Dai, Lehong Wang, Fangzhou Lin, Ziming Zhang, Wang Lu

European Conference on Computer Vision (ECCV) E.T. 2026

Real-world machine learning applications often face both distribution shift and label noise. We study semantic representations from frozen language models as domain-invariant anchors, and use a weighted loss that adjusts each sample's contribution based on its similarity to the corresponding language anchor, making models more robust to noisy labels while generalizing across unseen domains.

Frozen Language Anchors as Noise-Robust Priors for Domain Generalization under Label Noise: An Empirical Study

Zilin Dai, Lehong Wang, Fangzhou Lin, Ziming Zhang, Wang Lu

European Conference on Computer Vision (ECCV) E.T. 2026

Real-world machine learning applications often face both distribution shift and label noise. We study semantic representations from frozen language models as domain-invariant anchors, and use a weighted loss that adjusts each sample's contribution based on its similarity to the corresponding language anchor, making models more robust to noisy labels while generalizing across unseen domains.

DeformX: A Versatile Co-Simulation Framework for Deformable Linear Objects
DeformX: A Versatile Co-Simulation Framework for Deformable Linear Objects

Yi Yang*, Xiang Fei*, Lehong Wang*, Chenhao Li, Zilin Dai, Henry Kou, Lu Li, Howie Choset (* equal contribution)

IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) 2026

DeformX couples a Cosserat rod physics engine with NVIDIA Isaac Sim to simulate deformable linear objects such as cables and ropes with physically faithful dynamics, self-collision, and contact with free-form meshes, while rendering them realistically through mesh skinning. Fine-tuning SAM3 on DeformX data improves real-image wire segmentation by 10.2% mAP@75, and a rope-swinging policy trained purely in simulation transfers to a real UR5e arm.

DeformX: A Versatile Co-Simulation Framework for Deformable Linear Objects

Yi Yang*, Xiang Fei*, Lehong Wang*, Chenhao Li, Zilin Dai, Henry Kou, Lu Li, Howie Choset (* equal contribution)

IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) 2026

DeformX couples a Cosserat rod physics engine with NVIDIA Isaac Sim to simulate deformable linear objects such as cables and ropes with physically faithful dynamics, self-collision, and contact with free-form meshes, while rendering them realistically through mesh skinning. Fine-tuning SAM3 on DeformX data improves real-image wire segmentation by 10.2% mAP@75, and a rope-swinging policy trained purely in simulation transfers to a real UR5e arm.

WireSeg-32K: A Physics-Grounded Synthetic Dataset for Wire Instance Segmentation
WireSeg-32K: A Physics-Grounded Synthetic Dataset for Wire Instance Segmentation

Zilin Dai, Lehong Wang, Yi Yang, Xiang Fei

Synthetic Data for Computer Vision Workshop @ CVPR 2026

Wires and cables are hard to segment because they are thin, highly deformable, and frequently self-occluded, and instance-level annotations are expensive. We present WireSeg-32K, a synthetic dataset with 32,000 RGB images, instance masks, depth maps, and a real-world test set, generated by coupling Cosserat-rod dynamics with photorealistic Isaac Sim rendering. LoRA fine-tuning SAM3 on WireSeg-32K alone improves real-world mAP@75 by 10.2%.

WireSeg-32K: A Physics-Grounded Synthetic Dataset for Wire Instance Segmentation

Zilin Dai, Lehong Wang, Yi Yang, Xiang Fei

Synthetic Data for Computer Vision Workshop @ CVPR 2026

Wires and cables are hard to segment because they are thin, highly deformable, and frequently self-occluded, and instance-level annotations are expensive. We present WireSeg-32K, a synthetic dataset with 32,000 RGB images, instance masks, depth maps, and a real-world test set, generated by coupling Cosserat-rod dynamics with photorealistic Isaac Sim rendering. LoRA fine-tuning SAM3 on WireSeg-32K alone improves real-world mAP@75 by 10.2%.

From Flat to Form-Fitting: A Computational Geometry Approach to 3D Conformal Electronics Design and Rapid Prototyping
From Flat to Form-Fitting: A Computational Geometry Approach to 3D Conformal Electronics Design and Rapid Prototyping

Lehong Wang, Zilin Dai, Yuchen Wu, Ye Jin, Colm Barry, Tina Tian, Fujun Ruan, Shricharan Shastry, Rahul Panat, Gary K. Fedder, Howie Choset, Lu Li

IEEE International Conference on Automation Science and Engineering (CASE) 2025

We present a software pipeline that maps existing 2D PCB designs onto arbitrary, highly curved 3D surfaces and generates printing motions for aerosol jet additive manufacturing, removing the need to hand-design 3D circuit traces in CAD and enabling rapid prototyping of conformal electronics.

From Flat to Form-Fitting: A Computational Geometry Approach to 3D Conformal Electronics Design and Rapid Prototyping

Lehong Wang, Zilin Dai, Yuchen Wu, Ye Jin, Colm Barry, Tina Tian, Fujun Ruan, Shricharan Shastry, Rahul Panat, Gary K. Fedder, Howie Choset, Lu Li

IEEE International Conference on Automation Science and Engineering (CASE) 2025

We present a software pipeline that maps existing 2D PCB designs onto arbitrary, highly curved 3D surfaces and generates printing motions for aerosol jet additive manufacturing, removing the need to hand-design 3D circuit traces in CAD and enabling rapid prototyping of conformal electronics.

Fully FDM-Printed Soft Hand Exoskeleton

Zilin Dai*, Lehong Wang*, Markus P. Nemitz (* equal contribution)

ICRA Workshop on Emerging Technologies in Smart Exoskeleton Systems 2024

We design parameterized soft pneumatic hand exoskeletons that can be printed entirely on standard FDM printers, making personalized assistive devices affordable and easy to fabricate.

Fully FDM-Printed Soft Hand Exoskeleton

Zilin Dai*, Lehong Wang*, Markus P. Nemitz (* equal contribution)

ICRA Workshop on Emerging Technologies in Smart Exoskeleton Systems 2024

We design parameterized soft pneumatic hand exoskeletons that can be printed entirely on standard FDM printers, making personalized assistive devices affordable and easy to fabricate.

Vision-based FDM Printing for Fabricating Airtight Soft Actuators
Vision-based FDM Printing for Fabricating Airtight Soft Actuators

Zilin Dai*, Yijia Wu*, Haotian Liu, Lehong Wang, Markus P. Nemitz (* equal contribution)

IEEE International Conference on Soft Robotics (RoboSoft) 2024 (Oral)

Pneumatic soft robots are typically fabricated by manual molding. We propose a low-cost approach to improve the print quality of desktop fused deposition modeling by adding a webcam that monitors printing and detects and corrects defects such as holes or gaps, improving the air-tightness of printed pneumatic actuators without fine-tuning printing parameters.

Vision-based FDM Printing for Fabricating Airtight Soft Actuators

Zilin Dai*, Yijia Wu*, Haotian Liu, Lehong Wang, Markus P. Nemitz (* equal contribution)

IEEE International Conference on Soft Robotics (RoboSoft) 2024 (Oral)

Pneumatic soft robots are typically fabricated by manual molding. We propose a low-cost approach to improve the print quality of desktop fused deposition modeling by adding a webcam that monitors printing and detects and corrects defects such as holes or gaps, improving the air-tightness of printed pneumatic actuators without fine-tuning printing parameters.

In Search of Negative Moments: Multi-Modal Analysis of Teacher Negativity in Classroom Observation Videos
In Search of Negative Moments: Multi-Modal Analysis of Teacher Negativity in Classroom Observation Videos

Zilin Dai, Andrew McReynolds, Jacob Richard Whitehill

International Conference on Educational Data Mining (EDM) 2023

We build automatic and semi-automatic systems that combine speech emotion recognition, language analysis, and facial expression detection to find moments of teacher negativity in classroom observation videos.

In Search of Negative Moments: Multi-Modal Analysis of Teacher Negativity in Classroom Observation Videos

Zilin Dai, Andrew McReynolds, Jacob Richard Whitehill

International Conference on Educational Data Mining (EDM) 2023

We build automatic and semi-automatic systems that combine speech emotion recognition, language analysis, and facial expression detection to find moments of teacher negativity in classroom observation videos.

All publications