EIT week36-2 Actuators and Communication
Printed Electronics: Actuators and Communication
Overview
- Course: Engineering Interaction Technologies
- Professor: Michael Wessely, Interactive Matter Lab
Actuation Technologies
Sound Amplification Coil
- Mechanism:
Coil drives vibrating diaphragm: The coil is attached to a vibrating diaphragm. This diaphragm can be a material such as paper or plastic, and the vibrations produce sound.
Placed in a magnetic field: The coil is placed in a magnetic field created by a permanent magnet, which is labeled with north (N) and south (S) poles.
Input signal to the coil: An electrical signal is sent to the coil. This signal usually carries audio information.
Magnetic interaction produces sound: The electrical signal causes the coil to generate a changing magnetic field, which interacts with the magnetic field of the permanent magnet. Depending on the amplitude of the signal, the strength of this interaction varies, causing the attached diaphragm to vibrate at different frequencies and amplitudes, thus producing sound.
- Materials and Methods:
- Copper coils
- Fabric-based coils
- Vinyl cut, gold leaf, screen-printed silver, and painted silver coils
Heater
- Design: Utilizes a conductive layer arranged in coil or horseshoe patterns to distribute heat evenly.
- Functionality: Stacking multiple layers with conductive epoxy enhances heat production, suitable for thermochromic applications and reshaping elements in 3D prints.
- Mechanism: Conductive Layers: The heater contains one or more conductive layers, which can be formed from conductive materials such as conductive films or conductive coatings.
Distribute Heat Evenly: To distribute heat more evenly, these conductive layers are often designed in a coil-shaped or horseshoe-shaped pattern. This design helps the heat spread evenly across the surface.
Stack Multiple Layers to Generate More Heat: The total heat output of the heater can be increased by stacking multiple layers with conductive patterns. This stacking can be achieved by physically stacking the layers.
Connect Conductive Tracks: The conductive tracks on each layer are connected with conductive epoxy to form a single but larger heater. This connection ensures that current can flow efficiently through each layer to generate heat.
Shape Change Actuators
- Construction: Combines printed conductive traces with shape-memory polymers (e.g., polyethylene tape) that expand when heated above 90°C, causing actuation.
- Applications: Includes 3D printed configurations where heating modifies the surrounding material’s dimensions.
Communication Technologies
RFID Technology
- Components: Comprises an antenna and an RFID circuit, where the antenna harvests energy from an RFID reader.
- Function: The RFID circuit utilizes the harvested energy to transmit information back to the reader.
- Mechanism: Tag: A small device that contains electronic data. It can be passive (battery-free, activated by radio frequency energy provided by a reader) or active (built-in battery, can actively send signals).
Reader: A device used to receive and interpret data from a tag. The reader sends an radio frequency signal to activate the tag and read the information in it.
Antenna: Used to transmit and receive signals. Antennas can be embedded in readers or tags.
Data System: Used to process the data obtained by the reader.
Wireless Power Transfer
- Concept: Facilitates power transfer without the need for batteries, using paired sender and receiver coils.
Lab Applications
- Practical Implementations: Demonstrations include creating paper speakers, heaters, and shape-changing materials in lab settings, illustrating the practical applications of the discussed technologies.
Key Takeaways
- Integration of Actuators and Communication: The course explores integrating various actuation mechanisms and communication systems into printed electronics, highlighting innovative applications like sound production and wireless power transfer.