With our mission to create the longest battery life solutions for IoT, the Atmosic team has leveraged three technology vectors: Lowest Power Radio, On-demand Wakeup, and Managed Energy Harvesting. Our radio design lowers power to such an extent that we’ve reached a technology inflection point where the power usage is so low that Energy Harvesting is now a viable power source for standards-compliant wireless IoT devices.
Our Lowest Power Radio is a standards-based implementation of the Bluetooth 5 wireless platform. Our team’s extensive wireless and low-power experience has enabled Atmosic to achieve radical power performance improvements, while maintaining full standards compliance.
With On-demand Wake-Up, we have implemented two levels of listening, in essence, providing our radios with two sets of ears: one set provides the lowest level of “radio consciousness,” listening in a very slight “conscious” state to perceive incoming transmissions; the other set is a deep sleeper, waking infrequently, only when alerted to incoming signal transmissions by the light sleeping partner. This reduction in power-efficient listening results in significantly lower power consumption, while maintaining the speed and reliability required of many connected IOT devices.
Atmosic’s Managed Energy Harvesting takes battery performance to a heightened level, adapting system alertness to the environment.
Instead of relying on ambient energy harvesting, which is inherently less predictable, we favor a known energy source that can be controlled to guarantee robust functionality while minimizing the system dependence on battery power.
Photovoltaic Energy Harvesting
Since the development of the first silicon-based solar cell in the 1950s, photovoltaic technology has been dramatically improved. Today’s advanced solar cells have better durability and efficiency and can produce larger output voltages for a given light intensity. The electric power generated by a solar cell is directly proportional to its size. However, the generated power can vary drastically depending on the intensity of ambient light. The same solar panel can produce up to a 1000 times higher power under direct sunlight vs. in a typical indoor office environment. Solar panels are not exactly color blind either meaning that they will behave differently under different indoor sources such as incandescent, florescent and LED lights.
RF Energy Harvesting
RF energy beamed from an RF transmitter can be picked up by a receiver at a faraway distance and, if this detected energy is large enough, it can be used to power up the receiver electronics. While there are many sources of RF energy such as Wi-Fi routers and cellular devices around us, the overall ambient RF energy in a typical environment hardly gets large enough to be a reliable source to power today’s connected devices. However, if dedicated RF sources are strategically placed in the environment, they can beam RF power to a specific wireless node that is placed at a reasonable distance making the available RF energy at that node much higher than what is otherwise available ambiently. This “controlled harvesting” can then be used as a reliable method of powering remote devices.
Controlled RF energy harvesting is especially useful in powering electronics wirelessly in scenarios in which it is hard or impractical to replace batteries in a deployed wireless network. It is also useful when the network is deployed in difficult to access areas as in many industrial environments. RF Harvesting has the advantage that it can be available anytime when needed by simply turning on the RF source. The frequency of the RF signal can be anywhere within the unlicensed frequency bands of several 100s of MHz to several GHz. The lower the frequency the longer the range of the RF power transmission. However, lower frequencies demand proportionally larger antenna sizes for the harvester, which can be a factor in applications where the size of the harvesting node is constrained.
Thermal Energy Harvesting
A thermoelectric generator (TEG) is a solid-state device that generates electricity by exploiting temperature gradient in the environment. The amount of generated power depends on the temperature difference, as well as the amount of heat flux that can be successfully moved through the TEG device. The better the TEG construction is at moving heat from the hot side to the cold side and dissipating that heat once it arrives to the cold, the more power will be generated. Due to the need to maintain a temperature gradient, thermoelectric energy harvesting solutions can require larger form factors compared to other forms of harvesters in order to generate useful amount of energy.
Motion-based Energy Harvesting
There are two types of motion-based energy harvesters: (1) the more traditional ones using a coil and magnet, and (2) the ones based on piezoelectric effect. Coil and magnet-based harvesters can generate electric energy through the physical movement when a switch is flipped or when a door knob is turned. These types of motion-based harvesters are usually bulkier due to the size of their required components: a coil, a magnet and frequently a spring.
Piezoelectric energy harvesters generate electrical energy from mechanical strains, either in the form of continuous mechanical motion/vibration, or from intermittent strains such as clicking of a button. Because their small crystalline structure, piezoelectric harvesters are relatively small and light compared to other energy harvesting devices. However, their generated power can vary significantly depending on how regular and frequent the motion is.