Whackathon

Attaching the lever arm for final testing.

🗞️ Whackathon: Posture Correction for the Fatigued Engineer

Created for MakeMIT 2026 Hackathon

Project Overview

In the world of engineers, this posture is all too familiar: Shrimp Slouching Engineer In class, during office hours, in the dining hall—the "shrimp slouch" is an epidemic in the engineering community. But why do we slouch? Because there is no immediate consequence! There is no punishment for slouching besides vague back pain 10 years down the line... until now. Introducing Whackathon: The smart chair that fixes your posture in an instant with copious amounts of negative reinforcement.

Here's how it works:

Detection: Multiple distance sensors regularly spaced on the back of the chair detect exactly how far the user's back has strayed from the "Postural Ideal."
Judgment: The software looks at the sensor readings and determines if the sitter is slouching or merely "shrimping" 🦐.
Execution: The sloucher is punished via a two-stage system: first, a verbal roast; then, a physical whack.
Correction: Posture is fixed through Pavlovian conditioning!

What it does

When a person sits on the chair and opens the Whackathon app, they choose their "Monitoring Intensity" and duration. Upon pressing the "Start Monitoring" button, the system continuously tracks the distance between the chair back and the user's shoulders.

If found slouching, the laptop uses ElevenLabs' AI voices to roast the user aloud. If the user fails to "un-shrimp" within a 3-second grace period, the mechanical arm swings a rolled-up newspaper over and whacks the person on the head. It is effective, humiliating, and incredibly funny to watch.

How we built it

The system performs all computing on the host laptop via the app and uses Arduino Nanos to control the motors and receive input from the sensors.

Electrical System

The brains of the electrical system are two Arduino Nanos.

Nano 1: Reads input from six HC-SR04 ultrasonic distance sensors and communicates the filtered data to the second Nano.

Nano 2: Controls the motor logic and the LCD display. It interfaces with the laptop to trigger the "Punishment Protocol."

Actuation: A stepper motor pulls back the tension cord on the arm, while a high-torque servo motor acts as the "hair-trigger" release for the latch.

Mechanical System

The mechanical system is composed of a PVC pipe with a jointed end holding a roll of newspaper. The pipe has a high-tension elastic cord running its length, tensioned by an actuated pulley system. A latch stores this potential energy until the signal is received. When released, the pipe flings forward, and the jointed tip adds a "flick" motion so the newspaper lightly taps the user's head. A counterweight system ensures the arm returns to its resting position naturally via gravity, allowing the latch to reset for the next slouch event.

Software System

We built a desktop app in Python using PyQt6 for the GUI.

The Logic: A helper script processes sensor data to identify slouching patterns (filtering out normal movements like reaching for a coffee).

The Roast: When a slouch is confirmed, the app calls the ElevenLabs API to generate a custom roast. We chose a "Disappointed Librarian" voice profile for maximum psychological impact.

Challenges we ran into

We ran into two main issues: sensor calibration and mechanical alignment. On the sensor side, our ultrasonic sensors rely on a sound-reflective surface to get accurate distance readings. During our testing we realized that sitters with thick clothing got highly inaccurate readings and our sensors even showed that it did not detect anyone in the chair. We fixed this by having sitters only wear thin shirts or t-shirts. On the mechanical side we had multiple issues with the lever arm not aligning with the lath and servo motors. After a bunch of filing and tape we were able to secure everything correctly.

Accomplishments that we're proud of

We are super proud of our ability to keep a positive attitude throughout this very long process. We were also super proud of how well our project fit our design goals of being fun and entertaining.

How our project relates to entertainment

Getting comically whacked by a chair that insults your posture is funny, it just is. This chair is designed to bring the exaggerated comedic value that many engineering projects tend to lack. It transforms a boring ergonomic issue into a spectator (and participant) sport. By using ElevenLabs for high-quality voice acting and a newspaper for the whacker, we leaned into a "looney tunes" aesthetic that makes the user the star of a shrimp themed comedy sketch.

How our project relates to Sauron’s “Make Your House Fight Back”

A chair is a crucial part of the home, it exists on every floor, every room, and for every occasion. Your house needs you in good shape to take care of it; it's hard to mop the floors with crippling back pain. It's time to give your house the means to get you into shape. The Whackathon chair is perfect for a smart home to make sure you're still capable of doing your daily tasks that keep your home nice and shiny. It allows your house to fight back against bad posture and spinal decay.