John Goebel Portfolio

UNC Chapel Hill / NC State

About

B.S. Biomedical Eng. (2025) → M.S. Electrical Eng. (2026) → Ph.D. Biomedical Eng. (Current)

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I’m an Engineer focused on electronics and microdevices. My interests include smart implants, tissue biomechanics, and continuous wearable sensors. I'm currently working on my Ph.D. in Biomedical Engineering and M.S. in Electrical Engineering. In my free time, I enjoy mountain biking, baking, hiking, fishing, and chess. My goal is to build devices that improve lives and reduce suffering.

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Projects

In Progress: Laser Galvanometer and LED Filament Clock.

Autonomous 2D Magnetic Manipulation Device

March 2026

A weekend design project with my partner Payton in ECE 535. We built a 2D magnetic manipulation system that can autonomously move a small magnet ball to follow a square trajectory on a flat surface. The device includes a custom perf board PCB, 4 homemade electromagnets (steel cores and mag wire), and a custom platform (acrlic sheets and screws). The electronics utilize a 555 timer, CD4022 Johnson Counter, and N-MOSFETS with push-pull BJT's to drive the electromagnets. It would be fun to apply this concept to a clock in the future.

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Magnetic manipulation project image

Single-Ended Folded Cascode OTA w Baby Op-Amps

December 2025

This was my partner and I's first project using Cadence and my most humbling design experience. The goal was to design the fully differential folded cascode OTA using baby op-amps, but we ran out of time troubleshooting the circuit before the deadline and ended up with an incomplete/failed design of a single-ended folded cascode OTA and another simple OTA. Even though we fell short of perfect results, it was an amazing learning experience. I have never worked on a project with so many tightly coupled design variables in what felt like I was constantly chasing my tail. I have extreme respect for analog and RF design engineers.

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Single-ended folded cascode OTA Cadence circuit schematic
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Total Knee Replacement Goniometer

May 2025

Patients undergoing total knee replacement surgery often lack at-home resources to monitor their knee joint angle and range of motion during physical therapy. This electronic and wearable goniometer displays the joint angle in real time on a screen with Bluetooth compatibility. My role in this project involved all electronics, including designing a fully custom battery charging and regulation circuit, USB-C 3.1 communication, power delivery triggering, latching circuits for power and angle direction mode switching, custom ESP32 microcontroller circuitry, etc.

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Microplastic Detection System

April 2025

Micro- and nanoplastics are widespread contaminants found in human tissue and ecosystems, with unknown but potentially harmful effects. This work proposes an original and theoretical microfluidic device that separates and detects microplastics from oil and nanoplastics using acoustophoresis and electrochemical impedance spectroscopy. The device is built with standard microfabrication methods such as photolithography, electron beam evaporation, plasma bonding, etc.

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Building My Personal Portfolio Website

January 2025

I created this portfolio as a place to show my work and creativity. I hope to continually refine its design as I progress through my career. Building a personal portfolio has been on the back burner for the latter half of undergrad. I have no formal experience with front-end web development and wanted to challenge myself while having fun with this project during break (Winter 2025).

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Denoising 3D Magnetic Resonance Images: Implementation of Machine Learning Model

December 2025

This paper explores the application of Wasserstein-Generative Adversarial Networks (WGAN) for denoising 3D MRI scans, utilizing residual autoencoders and a custom loss function to enhance structural similarity and reduce oversmoothing. Compared to the state-of-the-art BM3D method, WGAN models show superior SSIM performance at higher noise levels, preserving structural details in MRI imaging.

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MRI Image
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Smart Tourniquet System

December 2024

Voted Best Project in NC State Graduate ECE Course by students. The tourniquet system dynamically responds to user heart rate and pressure fluctuations along the tourniquet membrane, aiming to reduce the the risk of nerve injury. The device integrates a microcontroller, pulse oximeter, accelerometers, pressure transducer, pneumatic pump, and solenoid valves to ensure precise pressure regulation.

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A Review on the Effects of Fourier Transforms and Convolution in Image Filtering

December 2022

This review explores the roles of the Fourier Transforms (FT) and Convolution in image processing. These mathematical operations are essential for transitioning between spatial and frequency domains, facilitating widely used methods in image analysis and filtering. The theoretical foundations of FT and Convolution are presented with examples to demonstrate their use. FT's may be used for deblurring and noise reduction, particularly in removing motion blur from images underneath the presence of noise.

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Evaluating Audio, Visual, and Tactile Reaction Systems

May 2023

This project investigates reaction times (RTs) across audio, visual, and tactile stimuli, utilizing a custom-built Arduino device for measurement. The methodology involved collecting 100 RT measurements for each stimulus type from myself, comparing these with online tests and a vibration-phone-tactile test to assess variance. Results revealed mean RTs of 190.3 ms (audio), 221.1 ms (visual), and 200.5 ms (tactile), with online and vibration-phone-tactile tests showing generally higher reaction times.

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Trading Strategy for Bitcoin and Gold

April 2022

This paper, from a competition freshman year, explores the application of Autoregressive Integrated Moving Average (ARIMA), linear regression, and polynomial regression models to predict prices in volatile markets like gold and bitcoin. Our aim was to maximize returns through strategic trading actions. By leveraging standard deviation channels and exponential ratios as trading indicators, the model identifies optimal buy/sell points within a seven-day window, considering transaction costs. The results demonstrate that the ARIMA model outperforms the market, achieving a total return of $610,000—significantly exceeding the $72,000 market return without trading actions.

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Experience

Academic and Industry Experience

Hi-PHI Lab – Chapel Hill, NC

August 2025 – Current

Electrical/Biomedical Graduate Research Assistant

  • Currently pursuing a Masters in Electrical Engineering and PhD in Biomedical engineering. I'm researching electromagnetic devices that measure and interface with the human body.
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Arthrex – Naples, FL

May 2025 – July 2025

Biomechanical Research Engineer Intern

  • Worked on biomechanical research investigating UCL surgical methods
  • Designed CAD fixtures in SolidWorks (e.g., spinal kinematic testing per ASTM Testing Standards)
  • Coded data extraction/analysis pipelines in Python (pandas, NumPy) for metrics such as Gap formation, Stiffness, Residual torque (Nm), Ultimate Torque (Nm), and Native Functional Zone
  • Performed cadaveric dissections
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Spinal Simplicity – Kansas City, KS

May 2024 – December 2024

Research and Development Engineering Intern working on spinal treatments.

  • Conducted biomechanical research on a treatment to enhance mechanical stability post-disc herniation repair and spinal fusion, aiming to reduce re-herniation rates and prevent adjacent segment disease
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Biomedical Electronics Teaching Assistant – Chapel Hill, NC

August 2024 – December 2024

Led two lab sections per week for a total of 30+ students, focusing on circuit analysis, binary math, and digital circuit design. Graded homework and lab reports while providing electronics guidance during lab.

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Skills

Technical Skills and Interests