Final Project — Responsive Kinetic Flower

Project Overview

This project focuses on the design and development of an interactive kinetic flower capable of opening and closing its petals in response to human presence. The system aims to simulate an organic behavior through a controlled mechanical transformation activated by electronic input.

The project integrates multiple domains of digital fabrication, including software design, 3D printing, and rapid prototyping using both additive manufacturing and low-fidelity materials such as cardboard. These processes were used iteratively to explore, test, and refine the geometry and functionality of the system.

From a mechanical perspective, the project is based on the transformation of motion, where a single input movement is distributed and translated into coordinated actions across multiple elements (petals). This required the development of a mechanism capable of converting rotational motion into vertical displacement, which then activates individual components in a controlled sequence.

The electronic system is built around a microcontroller platform (XIAO ESP32), integrating a PIR sensor as an input device and a servo motor as the output actuator. The system detects the presence of a user and triggers the mechanical response, creating a direct interaction between the environment and the object.

Beyond its technical implementation, the project explores the relationship between technology and perception. The goal is to move away from purely functional devices and instead create an artifact that evokes a sense of life, responsiveness, and subtle interaction, bridging the gap between engineered systems and natural behaviors.

Motivation

The motivation behind this project is to explore how digital fabrication, mechanics, and electronics can be combined to create interactive objects that go beyond functionality and engage users at a sensory and emotional level.

Rather than designing a purely technical device, the intention is to develop a system that behaves in a responsive and organic way, where movement is not only controlled but also perceived as natural and expressive. The project uses a flower as a medium because it represents a familiar and intuitive form of transformation, allowing the interaction to be easily understood while still offering complexity in its mechanical resolution.

This project is also driven by an interest in translating simple electronic inputs into meaningful physical responses. The challenge lies in bridging the gap between detection (sensor), decision (microcontroller), and expression (mechanical movement), creating a coherent system where each layer contributes to the final experience.

References and Inspiration

The conceptual direction of this project is influenced by artists and studios that work at the intersection of art, technology, and human interaction. These references are relevant because the project is not intended to be just a mechanical object, but an interactive artifact capable of responding to human presence in a subtle and engaging way.

• Refik Anadol — creates immersive environments using data and AI to generate emotional and sensory experiences through light, movement, and digital media.
• Random International — their installation Rain Room responds to human presence, allowing visitors to influence the environment through movement.
• Studio Roosegaarde — develops interactive installations that react to human behavior and environmental signals, combining technology, design, and public space.
• Neri Oxman — explores the integration of biology, material systems, and computational design to create responsive structures and material-driven design.
• teamLab — produces immersive digital environments where artworks react dynamically to visitor movement and presence.

At this stage, the exact mechanical solution is still under development. However, the direction of the project is clearly defined: to create a responsive kinetic artifact that merges art, design, and engineering through digital fabrication, generating a meaningful interaction between the user and the object.

Development Process

The development of the project followed an iterative process in which form, structure, motion, and interaction were explored progressively. Rather than starting directly with a final mechanism, the workflow began with a formal and material exploration of the flower, and then evolved through a sequence of mechanical tests, reference studies, and physical prototypes.

1. Initial Exploration: Static Form Study

The first stage of the project focused on understanding the geometry and visual language of the flower before introducing motion. Instead of starting with a mechanism, the process began with a static exploration to define form, structure, and modular organization.

a. Conceptual Direction

The initial idea emerged from observing natural leaf structures and organic growth patterns. These references were abstracted into a radial composition, where repetition and variation generate a complex overall geometry.

The goal was to translate organic forms into a system that could later be controlled mechanically. This meant simplifying natural geometries into repeatable and parametric elements.

b. 3D Modeling Strategy

The modeling process was developed in Rhinoceros, using a modular logic. A base petal was created and then distributed using a radial (polar array) system.

Each petal was generated using surface operations (two-rail sweep), allowing control over curvature and thickness. Although the petals share the same base geometry, their orientation changes depending on their position in the radial system.

This resulted in multiple variations of petals that together form a cohesive structure.

c. Modular Base and Organization

To organize the system, a hexagonal base was designed as the structural unit. This allowed precise positioning and repetition across the full geometry.

Each module was numbered to control assembly. Additionally, the base included a cavity underneath, improving stability and allowing better integration with the support structure.

d. Preparation for Fabrication

Once the geometry was defined, the model was prepared for fabrication. The petals were exported as STL files and organized in Bambu Studio.

Key decisions during slicing:

• Layer height: 0.12 mm for balance between detail and speed
• Material: PLA
• Thin wall detection activated
• No supports required due to controlled overhang angles

e. 3D Printing and Physical Results

The petals were printed in groups, allowing validation of both individual components and the system as a whole. Each print batch included multiple variations of the same geometry, ensuring consistency while testing orientation and surface quality.

Eeach petal required manual post-processing. Due to the thin geometry and the use of PLA, small imperfections such as stringing, rough edges, and minor surface inconsistencies were present.

To address this, each piece was carefully cleaned using manual tools, removing excess material and refining the edges to improve both aesthetics and mechanical behavior. This step was important to ensure smooth interaction between components during assembly.

After cleaning, the petals were manually heat-formed to achieve a more organic and dynamic curvature. Controlled heat was applied progressively, allowing the material to soften without deforming the structural base.

While the material was still flexible, each petal was shaped by hand to introduce curvature and variation, mimicking natural leaf behavior. This process transformed the initially rigid printed parts into expressive elements with a more organic appearance.

The final result demonstrates the transition from a purely geometric system to a more organic and material-driven form. This phase established the visual identity of the project and validated the feasibility of working with thin, deformable printed elements.

Key Learnings

• Separating geometry from final deformation allows better control of fabrication
• Modular systems simplify complex radial compositions
• Material behavior (PLA + heat) plays a key role in the final expression
• This stage defined the visual and structural foundation of the project

At this point, the project was still static, but it established the essential logic needed to later introduce movement.

2. Second Exploratión: Internal Cable System

Once the formal language of the flower had been defined, the next challenge was to introduce movement. The first mechanical strategy explored was based on an internal cable system integrated into the petals.

The intention of this approach was to transmit force from a central point toward each petal using flexible internal elements. In principle, this would allow a single input movement to activate multiple parts at once. The idea was attractive because it suggested a lightweight mechanism hidden inside the flower, potentially preserving the organic appearance of the petals.

The development of this stage involved testing how the internal path of the cable could be integrated into the petal geometry, how tension could be distributed, and how the petals would react when pulled from the center. This required thinking simultaneously about form, routing, anchoring points, and the deformation behavior of each element.

Key Learnings

However, this strategy introduced several difficulties. The geometry became harder to control because the motion depended on flexible behavior rather than guided movement. The response of the petals was not fully predictable, assembly became more complex, and the system required too much adjustment to maintain consistency. As a result, the motion lacked the precision and repeatability needed for the project.

This first mechanical exploration was therefore discarded, but it was still useful because it clarified an important design decision: the project required a more rigid and geometrically controlled mechanism instead of a system based primarily on tension and flexible transmission.

3. Third Exploration: Petal Lifting Mechanism

a. Reference Mechanism Study

After identifying the limitations of the internal cable system, the project shifted toward the study of an existing kinetic reference. A lotus-shaped opening mechanism was used as a case study to better understand how layered components can generate coordinated petal motion.

Instead of copying the reference directly, the purpose of this stage was analytical. A printed reference prototype was used to observe how movement was distributed, how multiple petals could open in a synchronized way, and how relative displacement between levels could be translated into a visible transformation.

This study made it possible to break down the mechanism into clearer principles. First, the motion was not dependent on flexible pulling elements, but on rigid parts that moved in a guided sequence. Second, the opening of the petals was controlled by geometry and contact, not by uncontrolled deformation. Third, layering the components made it easier to separate structural support from moving elements.

The most important outcome of this stage was conceptual: it changed the way the mechanism was understood. Instead of thinking about the flower as a soft object that needed to be pulled open, the project began to approach it as a coordinated mechanical system in which motion could be distributed through structure, levels, and controlled points of contact.

b. Development of Petal Lifting Mechanism

Based on the lessons learned from the reference mechanism, a third mechanical iteration was developed. In this version, the project moved away from cable transmission and adopted a direct lifting logic.

The new idea was to use a central mechanism capable of moving vertically. This movement would then activate one point under or near each petal. In this way, the petals would no longer depend on tension or flexible routing, but instead on a defined contact relationship with the central moving structure.

A central cylindrical structure was then introduced. This element acts as the main actuator, translating vertical motion into distributed mechanical responses across the system.

The next step was to explore how each petal could be mechanically connected to a structured base. A hexagonal modular system was used to organize the distribution of contact points, allowing a radial and repeatable logic across the entire surface.

Each hexagonal cell was designed to host a vertical element that would act as a lifting interface. This transformed the system into a field of discrete activation points instead of a continuous or flexible mechanism.

Additionally, a dedicated support for the PIR sensor was designed and integrated at the center of the main structure.

The design was fabricated; however, the intended movement was not achieved. As a result, the mechanism was modified by introducing defined support points for each petal. With this adjustment, when the central mechanism rises, it pushes these points and causes the petals to rotate into a closed position. When the mechanism descends, the petals return to an open position according to their geometry and support conditions.

Additionally, a structural base was designed to support the different levels of the mechanism. Some components are fixed to this base, while others are designed with clearances and guide rails to allow controlled movement. The base also incorporates space to house the electronic components in its lower section.

Several iterations were required to refine spacing, alignment, and interaction between components. Special attention was given to tolerances and clearances to ensure that the vertical elements could move without interference.

The system was then prepared for fabrication, validating the geometry through slicing simulations. This step helped identify potential issues such as unsupported areas, excessive material usage, and printing time constraints.

This new iteration offered several advantages. It simplified the system, improved the predictability of movement, and made fabrication more feasible. It also introduced a more modular structure, since each petal could be understood as an individual response unit connected to a larger central mechanism.

At this stage, the project was still under refinement, but the mechanical direction became much clearer. The system was no longer trying to imitate organic behavior through flexible complexity; instead, it began to build that behavior through structured motion and controlled geometry.

c. Physical Prototyping in Cardboard

Before continuing with more 3D printed iterations, especially the largest parts, a low-fidelity prototype was developed in cardboard. This stage was important because it allowed rapid validation of dimensions, spatial arrangement, and assembly logic without investing additional print time.

The cardboard prototype was used to check the scale of the flower, the radial distribution of the petals, the internal space required by the mechanism, and the general relationship between moving and structural parts. Because the material was fast and easy to cut, it provided a practical way to test the system at full scale and identify geometric issues early in the process.

This step confirmed that the overall arrangement was viable and that the internal volume and radial logic were working. More importantly, it helped separate which problems belonged to the geometry of the system and which were specific to the printed parts. In that sense, the cardboard model functioned as a fast decision-making tool rather than just a rough mock-up.

4. Final Development of Design

The final design of the project is currently still under development and testing. At this stage, the focus is on refining the CAD model to improve the integration between mechanical components, as well as optimizing geometries, tolerances, and assembly conditions. In parallel, adjustments are being made to the fabrication process to achieve a more precise and reliable final print. This includes improving print orientation, structural thickness, and overall stability of the components. The goal of this phase is to consolidate both the digital model and the physical output into a coherent and functional final system.

5. Electronics Development

The electronics of the project are relatively simple, but they are essential for enabling interaction. The system is based on three main components:

• PIR sensor → detects human presence
• Servo motor → drives the mechanical movement
• Microcontroller (XIAO ESP32) → controls the system logic

The interaction flow is straightforward:

• If presence is detected, the servo is activated.
• The opening and closing sequence is executed.
• If no presence is detected, the system remains at rest.

a. PCB Design and Fabrication

A custom PCB was developed to integrate the electronic system into the project. This allowed the components to be organized in a more compact and controlled way, while also adapting the circuit to the specific needs of the mechanism.

The process included:

• Schematic design
• PCB layout development
• Generation of fabrication files
• CNC milling of the board
• Soldering of electronic components

The board was validated through:

• Multimeter testing
• Oscilloscope measurements
• Real functional tests of the system

6. Failures and Lessons Learned

The difficulties encountered during the process were not simply failures, but important design decisions that had to be reconsidered.

• The cable-based system did not provide enough control.
• Thin printed parts failed structurally.
• The first versions of the mechanism were unnecessarily complex.

What proved most effective throughout the process was:

• Simplifying the mechanism
• Rapid prototyping, especially by testing first in cardboard
• Using real references to better understand movement
• Designing motion through geometry rather than relying on flexible elements

7. Current Status

At this stage, the project has reached a clear level of development:

• Concept → defined
• Electronics → functional
• Mechanics → under refinement
• Integration → still pending

8. Next Steps

The next phase of the project is no longer conceptual, but focused on execution and integration.

• Refine the petal design
• Adjust the central mechanism
• Fully integrate the servo into the structure
• Build a stable final version
• Validate the complete behavior of the system