Powering the Future of Sustainable IoT: World's Lowest-Power MCU

As AI, smart infrastructure, and connected devices spread into more parts of everyday life, the Internet of Things is entering another phase of growth. IoT analytics project that the number of connected IoT devices will exceed 40 billion by 2030, across buildings, industrial automation, healthcare, agriculture, and smart city infrastructure.

The problem is not connectivity. It is power.

Batteries remain the default answer for most IoT devices, but the costs accumulate quickly. A battery must be manufactured, transported, installed, replaced, and eventually disposed of. Multiply that by thousands of sensors in a building, or millions of devices across a product category, and battery life becomes an operational and sustainability problem rather than a line item on a datasheet.

Norwegian semiconductor company ONiO has taken a different approach: instead of asking how long a battery can last, it is designing connected devices to use energy already available in their environment.

Reimagining IoT Without Batteries

ONiO was founded around a simple but demanding idea: make useful, connected products without assuming that a battery has to be there.

Its ONiO.zero platform can harvest ambient energy from sources such as radio-frequency signals, light, thermal gradients, and vibration. In suitable applications, that energy can replace the battery entirely.

The platform is designed to work with a broad range of energy sources rather than one specific harvesting technology. ONiO.zero integrates an on-chip RF energy harvester and supports photovoltaic, thermal, kinetic, and piezoelectric sources. It operates across a supply range from 250 mV to 3.0 V and can be powered by harvested energy, capacitors, supercapacitors, secondary cells, or conventional batteries. That gives developers room to choose the energy architecture that fits the product.

ONiO.zero brings computing, wireless connectivity, memory, security, and power management together in a highly integrated wireless microcontroller. The difficult part is making all those functions useful inside the tiny energy budgets that harvesting can provide.

Setting New Standards for Ultra-Low-Power Computing

Battery-free operation starts with a very small power budget.

Independent EEMBC ULPMark®-CoreMark® results provide a useful reference point. In the published ONiO entry, energy, fixed voltage is 178 at 3.0 V and energy, best voltage is 181, also at 3.0 V; the performance score is 124. Those are the benchmark scores. ONiO's separate 22 µW/MHz figure describes power while running CoreMark from non-volatile memory at 4.1 CoreMark/MHz.

The device uses a custom 16/32-bit RISC-V RV32IMC processor, designed in-house rather than licensed, and combines that processing capability with the ability to cold-start from less than 1 µW of available power and sleep at well below 1 µW. For energy-harvesting products, those states matter as much as headline compute efficiency: the device must wake, do useful work, communicate, and return to sleep without exhausting the energy that has been collected.

ONiO.zero also integrates standards-based low-energy 2.4 GHz wireless connectivity, including IEEE 802.15.4 support for protocols such as Matter, Thread, and Zigbee RF4CE, along with sensor interfaces, energy-harvesting functions, and built-in security. Hardware-accelerated AES encryption, SHA-256 hashing, and a true random number generator are implemented in silicon, so security does not have to be treated as an external add-on.

The aim is not low power by removing functionality. It is useful wireless computing inside an unusually small energy envelope.

Sustainability by Design

That changes more than the energy bill.

Battery replacement can be one of the largest lifecycle costs in an IoT deployment, especially when devices are numerous, remote, hazardous to reach, or simply inconvenient to access. Harvesting energy from the surrounding environment can reduce maintenance, lower the total cost of ownership, and remove material from the eventual waste stream.

Consider electronic shelf labels. A mid-size supermarket can operate on the order of 50,000 labels, with two-coin cells in each label and a service life of around 18 months. That is roughly 100,000 batteries in one store, followed by another replacement cycle when those cells reach end of life. Remove the battery and you also remove much of the replacement labour and disposal that comes with it.

Elimination is not the only outcome. Where the available energy cannot carry the whole load, the same power architecture extends a conventional cell instead of replacing it, by roughly five to ten times. A coin cell that would have been changed every eighteen months can instead last the service life of the product. Across tens of thousands of devices that removes most of the same batteries and most of the same replacement labour, and it applies to a far wider range of products than harvesting alone.

The same logic applies across a wide range of IoT deployments:

• Smart homes and intelligent buildings
• Environmental monitoring
• Precision agriculture
• Healthcare and wearable devices
• Industrial IoT
• Logistics and asset tracking
• Smart city infrastructure

For some of these applications, battery-free operation is not merely a more sustainable version of the same product. It can make deployment practical in places, quantities, or form factors where routine battery replacement would otherwise be too expensive.

Engineering Innovation Powered by Cadence

Reaching those power levels is a system-level design problem. Processing, radio, memory, security, analogue circuitry, and power management all must be optimized together, across both analogue and digital domains. An improvement in one part of the device is not enough if another part consumes the harvested energy first.

ONiO used a comprehensive Cadence design flow to manage that complexity: Cadence Virtuoso Studio for analogue and mixed-signal design, the Innovus Implementation System for digital implementation, Xcelium Simulator and Jasper Formal Verification for verification, Tempus Timing Signoff for timing closure, and the Pegasus Verification System for physical verification.

ONiO CTO Vemund Bakken says the company selected Cadence as its sole EDA partner because of the breadth and integration of the environment and flexible licensing. Having tools available on tap is mandatory for a company like ONiO, where almost every single tool Cadence offers are used during the design cycle. These include analog capture and simulation in Virtuoso, synthesis with Genus, timing closure with Tempus, and place and route using Innovus.

Building a More Sustainable Connected Future

Extending battery life and removing the battery are the same engineering problem solved to different depths. What does not scale, in a world of billions of connected devices, is the assumption that somebody will come back to change them.

Energy harvesting changes the design question. Instead of sizing a product around the energy stored in a battery, developers can begin with the energy available in the environment and design the system to live within it. That is a harder constraint, but it can also remove maintenance cycles and open deployment models that conventional battery-powered devices struggle to support.

ONiO.zero shows how ultra-low-power computing, wireless connectivity, security, power management, and multi-source energy harvesting can be brought together on one platform. Cadence software and support have been part of the engineering path behind that integration, helping ONiO turn battery-free IoT from an aspiration into a measured semiconductor result.

As sensing becomes more pervasive, that shift matters: fewer batteries to replace, fewer batteries to discard, and more freedom in where connected devices can operate.