What is A Transducer?
There are many gadgets and gizmos we use in electronics prototyping, and among the more “foundational” devices is something called a transducer. A transducer is an electronic component that converts energy from one form to another. They are in our toolbox here at Loomia, and we highly suggest you add this device to yours. Read on to find out more about this essential component.
History of transducers
The foundational technology behind transducers is said to have been discovered as far back as the 1800s. A man by the name of James P. Joule was experimenting with iron and found that the material constricted when it encountered a magnetic field. Later in the 1800s, two men—Jacques and Pierre Curie applied a mechanical force to quartz crystals, which produced an electric charge. The conclusion that these materials could produce a mechanical strain was later made in the 1900s, and Transducers were in full production by the 1980s/90s.
How transducers work
As mentioned before, transducers convert energy from one form to another. And, they do this through a process called—you guessed it—transduction. When discussing wearable technology, there are two transduction methods that are commonly used in biosensing: amperometry and fluorescence. Amperometry is an electrochemical measurement of electron transfer, and fluorescence is the measurement of re-emitted light. We will get into more of this later.
Types of transducers
There are three main types of transducers we will be discussing, and they are Temperature Transducers, Piezoelectric Transducers, and Pressure Transducers.
Temperature transducers
Temperature Transducers convert thermal energy into mechanical energy and electrical signals. The sensor built into Temperature Transducers alter the properties of the sensing element when the temperature changes. Now, there are several applications for Temperature Transducers, but they are commonly found in products such as motors and appliances, as well as computers and electric radiators.
2. Piezoelectric transducers
Piezoelectric Transducers convert electrical signals produced by materials into energy. These transducers measure changes in pressure and strain, and create an electrical charge as a result of those measurements. You can find Piezoelectric Transducers in several electronics such as cell phones and printers. However, they are typically used in medical imaging devices such as ultrasound machines.
3. Pressure transducers
Also known as Pressure Transmitters, this transducer converts pressure into an analog reading. In Pressure Transducers such as those with a strain gauge, physical deformation of the strain gauge triggers the conversion of pressure into an analog reading. The strain gauge produces a resistance change that is proportional to pressure applied. Pressure Transducers can be found in automotive applications (air suspension monitoring), and wellness applications such as fitness machines.
Transducers vs actuators
The difference between transducers and actuators is straightforward: Transducers convert energy into an electrical signal, whereas actuators convert energy into motion. Additionally, actuators move and control a mechanism via an electrical current or pressure. Transducers do not move anything, but instead receive a stimulus which then produces a reading or set of information.
Transducers in wearables
In wearable devices, pressure sensors and temperature sensors are the most used transducers. And, they are used in a wide range of industries—from athletics to medical and consumer goods. Here’s how these sensors are used in the following application areas:
Athletic wear
Sports teams can have biometric sensors embedded in their uniforms to track health and performance metrics during games or training sessions. These sensors can monitor biological responses such as perspiration and heart rate, and turn it into actionable data.
2. Medical
In medical wearables, you will typically find pressure sensors embedded in garments and accessories. And, they are usually piezoresistive. These sensors can track vital signs such as blood pressure, and provide physicians with valuable information that can help them better diagnose conditions. The great part of having sensors in say, a t-shirt, is that the information they collect can be retrieved at a distance. There is no need for a patient to even enter the office!
3. Consumer goods
Sensors used in consumer electronics and wearables are used to enhance the user experience. Smart clothing, for example, is embedded with—sometimes removable—sensors that send data to an external device such as a smartphone. When wearable devices are mentioned, we jump to smartwatches. These have sensors as well, with some smartwatches and fitness bands containing as many as 16 sensors.
MORE TOOLS AND ELECTRONICS YOU SHOULD CONSIDER ADDING TO YOUR TOOLBOX:
From the Toolbox: Biometric Sensors
From the Toolbox: Conductive Materials
Looking to add e-textiles to your kit? Check out our range of Parts on Sparkfun! Loomia Parts are electronic components designed for making product-like prototypes, seamlessly integrating into the surface material of your choice. From fabric to wood, our components can stick onto a range of materials, making your prototypes look clean and polished.