- Pragmatic’s Flex-RV is a flexible processor that supports machine learning.
- Bendable, energy-efficient chip priced under $1.
Pragmatic Semiconductor, a UK-based startup, has launched Flex-RV, a ground-breaking 32-bit microprocessor that not only bends but also runs machine learning models—all for less than one dollar.
Flex-RV is based on the open-source RISC-V architecture and represents a significant step forward in flexible electronics, offering a cost-effective solution with a wide range of applications.
Flex-RV: Breaking away from traditional silicon
Integrating microprocessors into everyday items such as smart labels, healthcare wearables, or single-use medical devices has been impractical due to high costs and rigid form factors. These applications, which require minimal processing power and data bandwidth, have largely been overlooked by silicon-based solutions because of the high cost of traditional microprocessors.
Moore’s Law has propelled silicon to the forefront of the microprocessor industry for almost 50 years. Chips have got faster and more efficient over time, reducing in size from micrometres to nanometres and lowering their unit cost. Despite these advances, producing a silicon-based microprocessor for less than a dollar remains impossible for applications where cost is a significant consideration. Three main factors contribute to this limitation: the high capital costs of silicon fabrication plants, licensing fees for proprietary CPU instruction sets, and the costs associated with chip packaging.
- Silicon fabrication costs: State-of-the-art silicon fabs require enormous investment to produce advanced chips at small nodes (2-3 nm), and even lower-end chips are not cheap to manufacture due to ageing production methods in legacy fabs.
- Licensing and development costs: Many microprocessors are built on proprietary instruction sets (such as Intel’s x86 or Arm’s ARMvX), which come with significant licensing fees. Creating a custom instruction set also incurs substantial non-recurring engineering (NRE) costs.
- Chip packaging costs: Silicon microchips are brittle and need protective packaging to avoid breakage. This increases their cost and makes it harder to incorporate them into flexible applications such as wearables or implantable devices.
Enter Flex-RV: A flexible and efficient alternative
Flex-RV overcomes silicon’s rigidity by utilising indium gallium zinc oxide (IGZO) transistors, which can be printed on plastic at low temperatures. This eliminates the need for rigid, more expensive packaging. By integrating flexibility into the chip itself, rather than just its packaging, a host of issues related to corrosion and failure are resolved. In one demonstration, the chip was bent around a straw and continued to function—a feat that silicon could not achieve.
Although the flexibility makes for impressive visuals, the invention’s niche will not be where the circuit has to be constantly flexed in use; rather its flexibility will allow it to be shaped in specific ways that engender its use in unusual locations where traditional silicon technology would not be suitable. In short, the Flex-RV is able to flex, it’s not designed to flex constantly.
Although Flex-RV is not designed for high-performance tasks (as indicated by its 12,600 logic gates and maximum clock speed of 60 kHz), its energy efficiency is impressive, consuming less than 6 mW of power. Due to its slower speed, Flex-RV has not been specifically tested for energy efficiency in jobs requiring significant processing power. Despite this, the chip is well-suited to low-speed applications such as disposable medical devices, body-integrated electronics, soft robotics, and brain-computer interfaces.
Cost efficiency and open-source innovation with RISC-V
Flex-RV also distinguishes itself by utilising the open-source RISC-V architecture. Pragmatic Semiconductor avoided the fees associated with proprietary designs by choosing RISC-V, allowing the company to reduce the chip’s cost to less than a dollar. The RISC-V element ensures that Flex-RV is a solution suitable for a wide range of real-world applications, despite its limited processing capability.
Flex-RV has been tested to withstand bending up to a 5 mm radius curve without significant performance loss. This flexibility distinguishes it from earlier flexible electronics attempts, such as the Flexduino, which used rigid components on flexible printed circuit boards (PCBs). Flex-RV allows even the integrated circuit to bend, demonstrating a future in which flexible computer devices will be commonplace.
Pragmatic Semiconductor’s Flex-RV chip is a big step toward making flexible, energy-efficient, and cost-effective electronics a reality, with the potential to transform industries ranging from healthcare to consumer goods.
