Teardown 2026 // Portland Workshops

Feel the Difference

A Haptic Petting Zoo // Designing Immersive Tactile Experiences
Dillon Simeone

Deaf Lead Design Engineer

Universal Music Design

Location

DreamTENT @ Jupiter Original

July 25, 2026 // 3:30 to 4:50 PM

Welcome to the Haptic Petting Zoo

Most people have only experienced one type of haptic: phone vibration motors. Today you will feel many more.

SolenoidsSharp taps & clicks
ServosPressure & stretch
Thermal PlatesPeltier hot/cold
Audio FansAirflow haptics
Piezo ActuatorsHigh-voltage bend
ERMsRotary buzz
LRAsLinear resonance
Voice CoilBass shaker / transducer
Haptic KnobsDetents & ticks
Goals: sensor-to-haptic translation, cross-modal mapping, mechanoreceptor targeting
Every station has QR codes linking to full BOMs, source code, and build guides. All off-the-shelf parts.

Mapping Accessibility to Haptics

  • Universal Music Design bridges hearing and Deaf performance spaces through tactile overlays.
  • GestoLumina (Aalborg University Press): gesture-interpreted light, sound, and haptics framework.
  • Sonic Agency (ASSETS '25): technology-mediated performance by Deaf and Hard of Hearing musicians.
  • Haptic and light interfaces powered by ESP32s, with open documentation for makers at all levels.

For the Deaf and Hard of Hearing community,
programmable audio-reactive haptics
are not a novelty.

They are a sensory bridge.

Core Hardware: DFRobot Beetle ESP32-C6

Beetle ESP32-C6 ($4.90)
Beetle ESP32-C6
Ultra-compact for rings and wearables. LiPo charger inbuilt. RISC-V, WiFi 6, BLE 5, Zigbee / Thread / Matter.
ESP32-C3 Supermini ($1.75~)
ESP32 C3 Supermini
Great for ESP-NOW fleets, but no battery manager and single core.
CH32V003 ($0.50~)
CH32V003
The "ten cent microcontroller." Under $0.50 each, pennies on a reel. 5V-only with no 3.3V rail, so sensor options are narrower, but for driving motors it does everything you need. A CH32FUN talk at last year's Teardown got me started, and the tooling is genuinely as smooth as ESP-IDF.

Software: MicroPython vs PlatformIO

MicroPython

  • Real-time compilation. Edit, save, run. No build step.
  • Ideal for rapid prototyping and classroom workshops.
  • Higher power draw. The interpreter never sleeps as efficiently as compiled C.
  • Smaller library ecosystem. Many sensor drivers need manual porting.
  • Timing-critical code (I2S, precise PWM) is harder to get right.

PlatformIO

  • Compiled C/C++. Maximum performance, minimum power draw.
  • Massive library ecosystem. OTA, deep sleep, precise timing out of the box.
  • CLI is outstanding. One command to build, flash, and monitor any board.
  • Longer compile cycles. A full rebuild on a large project can take minutes.
  • Steeper initial setup (toolchains, board definitions, platformio.ini).

PlatformIO's CLI is the real superpower. It is language-agnostic. Shell out to pio run -t upload from Python, Node, Electron, or anything else, and you have a custom flash toolchain in an afternoon. The uploader below is exactly that: a thin web GUI over the CLI.

GestoLumina & UMD Journey

GELU 1
GELU 1 Felt Sound research to wireless ESP32-S3 and TensorFlow Lite gesture ML.
GELU 2
GELU 2 Iterative wearables, custom PCBs, and Bambu Lab rapid enclosures.
GELU 3
GELU 3 Scaling, commercialization, and recognizing wearable sizing challenges.
Haptic Gloves
Haptic Gloves Direct tactile feedback integrated into the knuckles.
SOLUTION: POCKETABLES
No shirt, no shoes, no service!

Mechanoreceptors: How We Feel

  • Pacinian Corpuscles: high-frequency vibrations (200 to 300 Hz), LRAs and transducers.
  • Meissner Corpuscles: low-frequency vibrations or slip (30 to 50 Hz), ERM buzzers.
  • Merkel Discs and Ruffini Endings: static pressure and stretch, servos and solenoids.

Actuator Modality 1: Solenoids & Servos

  • Merkel and Ruffini receptors respond to physical pressure and impact.
  • Solenoids: high-impact sharp taps and clicks, excellent UI confirmations.
  • Servos: steady, continuous pressure patterns and stretch sensations.
  • Pros: structural realism. Cons: heavy, bulky, power-hungry.

Actuator Modality 2: ERMs & LRAs

ERM (Rotary)
LRA (Linear)
  • ERM: asymmetric weight on DC motor. Pulse forward-reverse for sharp snaps, not 100% buzz.
  • LRA: mass on spring, crisp clicks at resonant frequency.
  • Resonant Frequency: driving off-resonance still vibrates, but wastes watts as heat instead of motion.

How Vibration Motors Work

  • Wire wrapped around a coil on a shaft, surrounded by magnets or more wire windings.
  • Current through the coil pushes the shaft against magnetic fields.
  • ERM: offset mass spins and throws the whole motor off balance.
  • LRA: mass shuttles back and forth on a spring at a tuned frequency.
DC Motor Rotor Diagram
Example of a 3-Phase DC Motor Rotor
DC Motor 3D Rotation Animation
How does an Electric Motor work QR
Watch: How does an Electric Motor work? (DC Motor)

How Motors Are Made

  • Brushed: coil on the rotor, magnets in the housing. Carbon brushes carry current to the spinning coil through a commutator. Simple, cheap, wears out.
  • Brushless (BLDC): magnets on the rotor, coils in the housing. An ESC switches coil phases electronically. No brushes to wear, but needs a driver IC.
  • The principle is the same: current through wire creates a magnetic field that pushes against another magnetic field, whether from permanent magnets or more wire windings.
  • PCB motors: coils etched directly onto a circuit board. Flat, ultra-thin, no mechanical winding. Limited torque, but ideal for coin-style haptic actuators.
  • Demagnetization: permanent magnets lose strength when heated past their Curie threshold. Ferrite starts fading at 80C. Neodymium handles more but is not immune.
  • In a closed wearable with no airflow, continuous duty can reach those temperatures in minutes.
  • Once demagnetized, the motor is permanently weaker. Cooling does not restore the field.
  • Takeaway: duty-cycle limits and thermal monitoring are not optional for wearable haptics.

Actuator Modality 3: Advanced Modalities

Actuator The Catch
Bass shaker Mini Bass Shaker (8 Ohm)
Requires AC audio power. DC offset or clipping causes overheating and self-destruction.
Piezo Piezoelectric Actuators
60V to 150V+ drive, specialized boost converters. Fragile to bending stress.
Peltier Thermal (Peltier)
12V 5.8A, massive heat sinks required or instant burnout.
Fan Fans / Air Haptics
Deafeningly loud when pushed to simulate strong wind.

Haptic Circuits: MOSFETs & H-Bridges

PWM Duty Cycle (audio-reactive ribbon)
DUTY CYCLE: 50%
  • GPIO pins output control signals, not high power.
  • MOSFETs: single direction for ERMs, LRAs, solenoids, Peltier.
  • H-Bridges: dual direction for active braking and dual-polarity actuators.
  • PWM maps frequency and amplitude to duty cycle for haptic intensity.

Power Delivery: USB-C PD Decoy

  • Heavy solenoids, Peltier plates, and transducers need more than 5V USB.
  • PD Decoy negotiates 9V, 12V, 15V, or 20V directly from USB-C chargers.
  • Configurable via DIP switches, less than one dollar each.
PD Module PD DIP settings

Free yourself from the tyranny of batteries!

Digital Signal Processing: FFT & Smoothing

CLICK OR PRESS ARROW TO ENABLE MIC
  • FFT separates audio into frequency bins. Map bass to body transducers, mids to hand LRAs.
  • Normalize and smooth: raw signals are jittery, use delta smoothing in non-blocking loops.
  • Rule of thumb: keep response times under 15ms with millis() scheduling.
  • Red, yellow, and blue motors below react to bass, mid, and treble bins in real time.

Audio-Reactive Sensing: MAX4466 & Telemetry

  • Low-Latency Transduction: The MAX4466 electret microphone module provides instant analog envelope extraction without I2S protocol overhead.
  • 3-Wire Workshop Interface: 3-pin hookup designed for rapid assembly on all Teardown Workshop Kits.
  • Direct ADC Pinout: Connect 3.3V and GND rails, then route the signal OUT pin directly to GPIO 6.
  • Single-Step Provisioning: In the Haxel device registry, select Analog Mic on Pin 6, hit save, and live telemetry stream begins immediately.
TEARDOWN WORKSHOP KIT PINOUT
VCC 3.3V Power Rail
GND Common Ground Reference
OUT GPIO 6 (Analog ADC Pin)
TACTILE ACTUATOR TELEMETRY
Driver: MOSFET | Actuator: ERM Mode: CLASSIC
Active: My Waveform (Studio)
CONNECTED

AUDIO-REACTIVE TELEMETRY

4.0x
40 Hz
16000 Hz

Frequency Band Partitioning

Maps acoustic audio frequencies into physical mechanical pulses for sensory substitution. Drag pins to resize frequency bands.

Haxel Expression Engine Cookbook

01

LFO Phase Accumulator

// Accumulate phase dynamically using dt
rate = 2 + sin(t) * 1.5;
phase = frac(phase + dt * rate);
wave(phase)
02

State-Variable Filter (SVF)

// Low-pass filter loop via dt integration
q = 0.4;
f = 6 * dt;
bp = bp + f * (noise(t * 3) - lp - q * bp);
lp = lp + f * bp;
clamp(lp, 0, 1)
03

Attack/Release Follower

// Fast attack, slow release
target = square(t / 2, 0.5);
k = target > env ? 12 : 2.5;
env = env + (target - env) * min(1, dt * k);
env
04

Decaying Noise Burst

// pow(2.718, -x) is e^-x: natural decay
envelope = pow(2.718, -5 * (t % 1.5));
noise(t * 20) * envelope

Existing Wearables: Success vs. Failure

Woojer Vest

Woojer Vest

Plug and play like headphones, but limited to 0 to 250 Hz, peaking near 42 Hz.

Haptic Shoes

Haptic Shoes

Expensive, not easily shared, not easily washed.

Buttkicker

Buttkicker

Powerful but stationary. Works with any chair. Your downstairs neighbor will hate you.

Safe Wearable Design & Thermal Reality

  • HAVS: prolonged strong vibrations cause permanent nerve and vessel damage.
  • Strobing effects can trigger seizures. Stay outside photosensitive frequency zones.
  • Never place active haptics on eyeballs (immune-privileged area).
  • Material safety: avoid nickel, latex, and cheap adhesives on wearable straps.

SAFETY FIRST: software timers, physical guards, and fleet E-stop before every demo.

Thermal Reality: Motors heat up fast. Closed wearables can demagnetize or burn skin in minutes. Always enforce duty limits, active cooling, or heatsinks.

Petting Zoo Stations & Q&A

HAXEL

HAXEL Portal QR

dillonsimeone.com/Projects/Haxel/index.html

Support Dillon (Venmo)

Venmo QR Code

Verification (last 4 digits): 7082

Smartphone Haptics

Smartphone Haptics QR

dillonsimeone.com/MiniProjects/smartphoneHaptics/index.html

Thank You!

Speaker Notes (N to toggle)

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