Introduction

In this project, we sought to create an object that would respond to an emotional stimulus. We wanted the device to connect to users at a personal level and so, we came up with the Anxious Little Individual (A.L.I.) which responds with fear and anxiety just as a person would.

A.L.I. is able to detect loud noises which causes it to vibrate and shake nervously, letting the user know that it is scared. This reflects how we respond to reprimands or harsh sounds.

aThis one-in-one-out system converts the sound input into motion. An Electret microphone detects the input, and a small DC motor with an unbalanced weight generates the vibrations.

Video

Technical Notes

Mechanics

The robot’s body was made from lightweight cardboard which vibrates easily. The robot’s body was propped up on springs to further enhance its motion. To generate vibrations from the motor, we attached an off-center weight to it. Also, to prevent sound and vibrations from the box causing feedback with its microphone, we insulated the microphone from the box by wrapping it in a neoprene sleeve.

Electronics

The microphone detects loud sounds within approximately a foot in front of the A.L.I., and converts the sound waves to an electrical signal. The signal is raised to 5 volts by a step-up regulator, causing a MOSFET to turn on and trigger the motor.

Circuit Diagram of the device

Issues/Observations

• Mic Sensitivity
  • One of the first challenges we faced with this project was determining the appropriate level of sensitivity of the microphone. If it was too sensitive, quiet voices would still be able to set off the motor. If the sensitivity was too low, the mic would not register the signal to the motor. Using trial and error, we determined which setting would give us the best results.
• Noticeable Vibrations
  • At a higher voltage, the motor would spin faster – if the motor spun too quickly, the overall effect would be a vibrational hum in which it was difficult to discern a shaking motion from A.L.I. We discovered that by lowering the voltage and having the motor spin slower, the vibrations were more evident and noticeable. We also determined that attaching the motor to the side of the box rather than the floor of the box gave better results.
• Transferring the circuit from the breadboard to the actual device
  • When initially soldering the components onto the device, the circuit failed to work as it had initially done in the prototype. After clearing up excess wiring and taping them down, the device began working as expected.

Initial Circuit Prototype

Springs attached to the Base

Neoprene Sleeve for the Mic

Dimension Sketch

Overall Structure

Completed Wiring

Final Product