Mechanical Flowers
Mechanical Flowers
Resources for Micro:Bit
Purpose
The BBC microbit is a tiny computer that can be programmed to control motors and lights - but what those motors and lights do is up to you!
This internship project aimed to find creative and artistic ways to use the microbit by creating mechanical flowers that would respond to sensors.
The intern working on the project was Thomas Lamb.
Read through the sections to see how each component works in the mechanical flower model, and then have a look at the How To guides in the Extra Resources section.
Where have these resources been used?
- Mechanical flowers have been designed by students attending the Royal Institution Engineering Masterclasses at Warwick (2025).
- Thomas Lamb's internship project with the WMG Outreach team developed electronics and mechanical linkages for additional paper flowers, as well as a 3D printed version.
Video of the mechanical flowers:
View the video of the mechanical flowers in full screen by clicking here.Link opens in a new window
Context
The mechanical flower project started with paper models. The mechanisms were controlled by paper hinges, thin wire, and straws.
Realising that these models provided a creative and artistic way to explore mechanisms - things that are typically only seen or imagined in gigantic factories - Margaret Low began to build simple models of these flowers that students could program and control during visits to the University of Warwick, or in schools.
An internship in 2025 - run by Thomas Lamb - developed these paper models and added sensors that could control the movement of the flower.
Tom also developed a 3D printed version of the flower to be a more 'engineered' display model, but still based on the same principles of the paper versions that students could replicate.
The WMG Outreach team are now looking into ways to display these flowers, the mechanisms that move them, the electronics that move them, and the code that controls them to more audiences. Hopefully, this will show how easy code, electronics, and mechanisms can combine to make beautiful creations!
Mechanism - linear actuator
The mechanism uses a plastic linear actuator connected to a servo motor that
moves a rod up and down. The rod drives a mobile collar around the stem, which is typically a straw. Linkages connect the collar to the outside of the petals, which are hinged at their base. As the rod moves downward, the petals are pulled open, and as the rod moves upward, they are squeezed shut, creating a blooming effect.
Click here to see a video the linear actuator moving.
Electronics
The microbit is the perfect choice for the microcontroller in this project. It has pins that can be connected up to motors (in the picture below, a servo motor), leaving other pins free to connect to control elements (such as switches) or sensors (light dependent resistors, motion sensors, force sensors).
Control - sensors
In the Force Sensitive Resistor (FSR) version of the flower, the petals remain closed when no pressure is applied to the touch plate. A medium press causes the flower to open halfway, while a firm press opens it fully. The code uses status indicators and threshold ranges to measure the applied pressure and determine the corresponding petal angles, allowing the flower to respond dynamically to different levels of touch. The underlying mechanism is like the other models, with a rod moved by a servo motor, a mobile collar around the stem, and linkages connecting the collar to the hinged petals.
Light dependent resistors can be used to create a flower that opens when it is light, and motion sensors can be used to make a flower that opens when someone walks past it.
Designing a 3D printed flower
Each petal is hinged at its base and fixed to a stationary hub at the centre. Running through that hub is a threaded rod, rotated directly by a motor. A sliding nut travels up and down this rod, fixed in place by the surrounding petals so it cannot spin, only move vertically. Linkages connect the nut to every petal, so as the nut rises, the petals fold in, and as it lowers, the petals spread outward into a full blossom.
Mechanisms and linkages
A metal-geared servo motor powered the movement, handling the load reliably but with noticeable noise.
The design evolved to a stepper motor, providing smoother, quieter, and more precise control of the blooming motion.
Video - 3D printed flower opening
Moving the flower
The first prototype featured six identical petals, perfectly symmetrical and aligned to form a closed bulb when shut. Each linkage connected to the centre of a petal, giving strong leverage for opening and closing.
The petals were engineered for precision, opening and closing in perfect unison. A ring of LED lights at the base lit up in time with the petals, creating a glow as the flower moved.
The final design (closed)
In the next prototype, the linkages were moved closer to the base, reducing how much they protruded into the overall flower display. The shape of the petals was also altered to resemble a tulip more naturally, with neighbouring petals overlapping to give the model more depth. The motion of the threaded rod was reversed, extending less upwards and more downwards. In this version, the mobile fixing moved downward through the centre of the flower to close the petals and upward to open them. This allowed more of the mechanism to be hidden below the flower, showing off the petal structure.
The final design (open)
The electronics were mounted below in a custom 3D printed flowerpot. A light-dependent resistor detected the presence of a torch beam, causing the flower to open when illuminated and close when the light was removed. A force-sensitive resistor was also added to cycle through different LED colour options for the flower. A stepper motor was used to drive the threaded rod instead of a servo, providing quieter operation and more precise step control.
