Welcome to the virtual presentation of MorphingCircuit, an integrated design,
simulation, and fabrication workflow for self-morphing electronics.
Recently, we have seen a boom of non-planner
surfaces equipped with functional electronics,
which enable sensing and display directly on the surface of a product.
However, manufacturing such non-planner
electronics often require specialized manufacturing processes and materials.
Furthermore,
most of the existing techniques are incompatible with complex geometries.
What if we utilize the materials' ability
of shape transformation, such that a circuit can be manufactured
in a planner version and then transform to a complex 3D structure?
In response, we introduce MorphingCircuit, an integrated design, simulation,
and fabrication workflow that combines electronic functions with forms,
which efficiently reduces cost, production time, and e-waste.
MorphingCircuit has its unique advantages
over existing circuit fabrication techniques.
Particularly, it is a self-morphing
technique for manufacturing circuits with complex curvilinear surfaces.
Here, the morphing occurs during the manufacturing process.
A flat sheet can self morph into 3D complex geometry.
Then how to achieve the self-morphing electronics?
Actually, our group has been working on self-morphing interfaces for a while.
For example, we developed a series of 4D printing techniques
to achieve origami self-morphing structure,
reversible self-morphing structure,
mesh topology based large-scale structure,
linear self-morphing structure for compliance mechanism,
double-curvature structure for continuous surfaces,
3D self-morphing structure for shrinkable adaptations.
Accordingly, we aimed to integrate self-morphing techniques with electronics due to the integration of conductive traces.
Morphing a circuit is not as easy as we thought.
For example, we took three basic morphing mechanisms as our mechanism verification
test samples, which are twisting, bending, and coiling, respectively.
The top row pictures are pieces without traces.
The bottom row pictures are pieces with traces.
All the traces significantly affect the morphing preference.
To mitigate the effect of the traces
and optimize the trace placement, we developed a simulation tool based on FEA method
and the residual stress releasing computational model.
The blue color represents the minimum-stress area,
which is also called the golden area.
Since the area is with the smallest value of stress,
it is recommended to align and print with a silver trace.
That means if we print the traces
on the golden area, it should be the least influenced.
The experimental results show that with traces printed on the golden area,
the transformation is much less influenced
than those with traces printed on the non-golden area.
Then we integrated the simulation tool in design and fabrication process.
To achieve MorphingCircuit
take the three-leg robot as an example.
Users start by creating a profile of a 2D
substrate and assign an actuator type for each chosen block.
Then the simulation platform helps to predict the transformation and suggest
preferable areas where the traces can be applied utilizing the simulation result,
the next step is to design a PCB schematics.
For the fabrication process. We applied conductive traces with a standard screen printing process,
and we suggest using a spacer to lift up the side for double-side traces.
We designed sinks on the substrate for electronic components to settle in.
After assembly, we applied extra silver ink to the connection points.
Then we put the whole piece in the oven for triggering and silver ink curing.
This is a light chasing robot with integrated surface mount,
photodiodes, transistors, vibration motors, and a battery.
When light is shining, the robot will move to the path of light.
We can also design an interactive
and portable product like this Christmas tree with touch sensing and hover sensing.
When the user first touches the tree near the silver traces, all LEDs turn on.
Then we can use hover motion to control its brightness.
As you can image
this kind of shape with electronics is hard to achieve with conventional 3D printing
like injection molding or vacuum forming technique.
Here is another interesting application area
we can utilize the morphing structure to prototype tunable electronic components
such as capacitor, resistor, inductor, and switch.
Each component can be printed with a custom shape and desired value range.
This is a conductor.
We can tune its value by designing different sizes of spring.
This is a switch.
By locking the edges to different
positions, different colors of LEDs are lighting up.
This is a capacitor.
We can tune the value by controlling the distance of the two panels.
Beyond screenprinting silver traces
we can coat the conductive layer using a standard sputter coater.
This is the transforming process.
In hot water, we use this structure as a capacitive humidity sensor.
After treating, we put two of them in the soil.
It shows that when the user pours water
to their plants, two visualized bars are shown.
Last, we envision these MorphingCircuit applications
can extend the boundary of our Galaxy
of self-morphing technologies and inside a search for even
larger design spaces of self-morphing interfaces.
Thank you