Xitong Sun

📝 Research

Conductive-Silicon-Packaged Piezoelectric Resonators

Advised by Prof. Ruochen Lu · UT Austin
Apr. 2026 – Present

Designed a conductive-silicon package for piezoelectric resonators, demonstrated with LiNbO₃ in a Si–LN–Si stack, to improve power handling, avoid electrode breakdown and enhance heat dissipation.

• Demonstrated capacitive excitation of LN through Si–LN air gaps using conductive Si electrodes, retaining 95% of bare-LN Q and 99% of bare-LN k².
• Fabricated Si–LN–Si resonator prototypes using multiple bonding methods (Au–Au, BCB, photoresist and Crystalbond) and evaluated their effects on resonator performance.
• Evaluated packaging effects on power handling and thermal performance under high-power excitation.

Vertically Stacked LiNbO₃ Isolation Transformers

Advised by Prof. Ruochen Lu · UT Austin
Mar. 2026 – Present

Designed a vertically stacked LN–sapphire–LN isolation transformer for mechanically coupled power transfer across an electrically insulating layer, targeting high power handling and high breakdown voltage.

• Simulated mode shapes and admittance spectra of 36°, 128° and 163° Y-cut LN in COMSOL; optimized layer thicknesses for half-wavelength resonance to improve acoustic transmission.
• Fabricated two-port transformer prototypes and designed test PCBs with corner-fixed mounting and wire-bonded electrical interconnects.
• Currently characterizing resonance frequencies, Q and k² using VNA measurements; evaluating nonlinearity, power handling, temperature coefficient of frequency (TCF) and power-transfer efficiency.

Modeling and Control of Multiphase Buck Converters

Advised by Prof. Yicheng Zhu · UT Austin
Feb. 2026 – Jun. 2026

A modeling and simulation study of how feedback-control strategies affect multiphase buck dynamics and regulation.

• Developed state-space-averaged and small-signal models of multiphase buck converters; analyzed converter dynamics and loop-gain characteristics for feedback-controller design.
• Implemented voltage-mode, current-mode, COT and V² control in PLECS; evaluated closed-loop stability through frequency-domain analysis and dynamic regulation through time-domain simulations.
• Compared transient responses across different control strategies, quantifying trade-offs in voltage deviation, settling time and implementation complexity.

MEMS Gas Sensor Arrays with Wafer-Level Material Patterning

Advised by Prof. Fei Wang · SUSTech
Jun. 2023 – Apr. 2025

Wafer-level fabrication and data-driven gas identification using multi-material MEMS sensor arrays.

• Optimized a backside-etched microheater structure, reducing heating power consumption by 25% compared with the frontside-etched design.
• Developed a wafer-level multi-step photolithography process for patterning multiple gas-sensing materials on MEMS sensor arrays, and fabricated devices through lithography, deposition and etching.
• Applied support vector machine (SVM) models to sensor-array responses, achieving 100% gas classification accuracy and R² ≥ 0.98 for concentration prediction on a test set.

📄 Publications

1. MEMS Gas Sensor Arrays with Multilayer of Nanomaterials Patterned by Wafer-Level Photolithography Process, X. Sun, J. Li, T. Cheng, and F. Wang^*, Transducers 2025, Orlando, FL, USA, pp. 1061–1064.
2. MEMS Gas Sensor with On-chip Electrospun Ru-SnO₂ Nanospheres Patterned by Photolithography, J. Li^†, X. Sun^†, T. Cheng, and F. Wang^*, IEEE SENSORS 2024, Kobe, Japan, pp. 1–4.
3. MEMS Acetone Gas Sensors with Eu-doped SnO₂/In₂O₃ Nanofibers Using Electrospinning and Lithography Patterning Technique, T. Cheng, J. Li, G. Niu, X. Sun, and F. Wang, IEEE SENSORS 2024, Kobe, Japan.
4. MEMS Gas Sensors with Metal-Oxide Semiconductor Materials Patterned at Wafer-Level by Photolithography Technique, X. Liu, G. Niu, J. Li, Y. Zhuang, X. Sun, and F. Wang, IEEE SENSORS 2023, Vienna, Austria.

📚 Course Projects

😎 Play Hard

I graduated from Southern University of Science and Technology in 2025. I am deeply grateful to all the teachers, friends and family members who supported me along the way. SUSTech gave me countless precious memories, which I will keep in my heart forever.

I'm also a big fan of classical music. I spent four joyful years with the SUSTech Philharmonic, and one year as orchestra president. I participated in more than 20 performances. I also enjoy attending concerts and have heard memorable performances by the San Francisco Symphony Orchestra, New York Philharmonic, National Symphony Orchestra, Austin Symphony Orchestra, and West-Eastern Divan Orchestra. My favorite piece is Sibelius’s Violin Concerto in D minor.

I also love traveling and exploring different landscapes. Yosemite is my favorite national park.