Manuel Ignacio Ayala Chauvin

1. Introduction

Storytelling is a powerful tool for stimulating children's imagination, improving language comprehension, and strengthening the bond between the narrator and the listener. This project aims to design and build a sponge puppet with an internal mechanism that synchronizes facial movements with narration.

2. General Objective

Design and construct an interactive sponge puppet with a movement mechanism synchronized with the voice, making storytelling more engaging for children.

3. Specific Objectives

• Design an internal structure that enables mouth movement and basic facial expressions.
• Use accessible materials and digital fabrication techniques to build the puppet.
• Implement an activation mechanism based on servo motors controlled by an electronic board.
• Develop an automatic synchronization system between narration and mouth movement.

4. Justification

Puppets have been used for centuries as educational and entertainment tools. However, most require manual manipulation, limiting immersion in the story. This project seeks to create an interactive puppet that enhances the storytelling experience, offering a more dynamic and immersive way to tell stories.

5. Methodology

Stage 1: Definition

The equipment specifications are established, including technical requirements and constraints.

Stage 2: Conceptual Design

Solution principles and the basic design structure are developed.

Stage 3: Materialization Design

General drawings are created, and prototypes are built to validate the concept.

Stage 4: Detailed Design

Manufacturing plans and part specifications are prepared for production.

5.1 Product Specifications

Product Objective: Develop an interactive sponge puppet that synchronizes facial movements with storytelling narration, enhancing children's storytelling experiences.

Functional Requirements

• Mouth and facial expressions synchronized with the narrator’s voice.
• Real-time response to audio signals.
• Simple user interface for control and configuration.

Non-Functional Requirements

• Use of safe and durable materials suitable for children.
• Minimum autonomy of 2 hours of continuous use.
• Ergonomic and visually appealing design for children.

Constraints

• Maximum budget of $700.
• Compliance with toy safety regulations.
• Size and weight limitations for easy handling.

Specification Table

5.2 Conceptual Design

Based on the specifications, multiple concepts are generated to meet the established requirements. Each concept is evaluated considering factors such as technical feasibility, cost, ease of manufacturing, and user experience. Tools such as function diagrams, sketches, and preliminary models are used to visualize and communicate ideas.

Optimal Concept Selection

A decision matrix is used to compare the different concepts developed in the previous phase. Criteria considered include:

• Compliance with functional and non-functional requirements.
• Estimated production cost.
• Ease of assembly and maintenance.
• Potential user acceptance.

The concept with the highest score will be selected for detailed development.

5.3 Materialization Design.

Mechanical Design

• 3D modeling of the puppet's internal and external structure.
• Specification of materials and mechanical components, including servo motors and transmission mechanisms.
• Tolerance and adjustment analysis to ensure optimal functionality.

Electronic Design

• Circuit schematics and selection of electronic components, including microcontrollers, audio sensors, and communication modules.
• Printed Circuit Board (PCB) design and component layout.
• Firmware development for motion control and audio signal processing.

Aesthetic and Ergonomic Design

• Selection of colors, textures, and shapes to make the puppet attractive to children.
• User interface design, ensuring an intuitive and user-friendly interaction.
• Ergonomic considerations for easy manipulation of the puppet by storytellers.

5.4 Detail Design.

The Detail Design is the final phase in the development process of a product, system, or engineering project. In this stage, all the necessary elements for the manufacturing, assembly, implementation, or construction of the final product are precisely defined.

This methodology, inspired by Concurrent Engineering and Integrated Product Development approaches, ensures that all disciplines work in a coordinated manner from the initial stages of the project, minimizing rework and optimizing the development process of the "Sponge Puppet with Mechanism for Storytelling".

The image shows an articulated bar system (four-bar linkage) that allows the “mouth” (the red shape on the right) to move by means of a motor and a return spring. Below is a description of its components and how it works:

5.4.1. Main Components

• Case with Electronics: Contains the circuitry and control system for the motor.
• Motor (D): This is the source of motion; when its shaft rotates, it drives the bar connected to it.
• Articulated Bars (A-B-C-D):
  • Each point (A, B, C, D) is a pivot or axis of rotation.
  • The bar attached to the motor (point D) transfers the motion to the next bar (point C), and so on.
• Spring: Responsible for providing a return or stabilizing force. It can close the mouth when the motor is not applying force or, depending on the design, help keep it open.
• Mouth/Red Contour: This is the part to be animated. The bar mechanism causes this part to rotate or open/close when the motor moves.

5.4.2. Operation of the Four-Bar Linkage

The motor (D) rotates, driving the drive bar attached to its shaft. That bar is connected to the next one (at pivots B and C), so that the motion is transferred to the final piece, which is the red “mouth.” The spring helps return the mouth to its initial position or maintain a constant tension, depending on the design.

5.4.3. Purpose and Advantages of the Design

• Controlled Opening and Closing: The mouth’s opening angle is determined by the length of the bars and the position of the pivots.
• Smooth Movement: Being an articulated bar system, it achieves a smooth and repeatable motion.
• Automatic Return: The spring makes it easier for the mouth to return to a “closed” or “neutral” position without requiring additional power from the motor.
• Mechanical Simplicity: Since it does not require gears or complex systems, the four-bar linkage is easy to maintain and adjust.

Overall, this mechanism makes it possible to animate the puppet’s “mouth” for a storytelling project, where the motor drives the opening and the spring aids in closing (or vice versa), providing a controlled and precise movement effect.

6. Expected Impact

• Improvement in storytelling experiences.
• Increased attention and interaction from children.
• Use of accessible technologies for education and entertainment.