Flexible: British startup Pragmatic Semiconductor has unveiled a 32-bit microprocessor that can run machine learning models while also being bendable – all for under a dollar. Named Flex-RV, this chip is based on the open standard RISC-V architecture and utilizes an entirely different material to achieve its highly adaptable design.
That material is called indium gallium zinc oxide (IGZO), which replaces the more conventional silicon. The key innovation lies in avoiding the complex (and expensive) packaging that silicon chips require to protect their brittle nature from the stresses induced by flexing. Instead, IGZO transistors can be printed directly onto plastic substrates at low temperatures.
Pragmatic's demo showcases the Flex-RV being rolled up around a straw and then unfurling to continue executing code undisturbed. While the demonstrator handled the board with extra care – suggesting you can't exactly flap it around – watching it curl up and keep computing was still a pretty impressive feat.
Don't expect blistering performance, however. With only 12,600 logic gates, the Flex-RV prototype achieves a maximum clock speed of 60 kHz – that's 0.00006 GHz in PC gamer terms. Despite these modest performance numbers, the chip successfully integrates a low-power machine learning accelerator.
Pragmatic never intended the Flex-RV to train GPT-4 models. Consuming less than 6 mW of power, this ultra-efficient chip is ideal for powering disposable medical devices and a new frontier of flexible, body-conforming gadgets, such as improved health wearables, soft robotics, and even brain-computer interfaces. Additionally, by leveraging the free, open-source RISC-V instruction set, Pragmatic has avoided the pricey architecture licensing fees that typically inflate chip costs.
In testing, the resilient processor maintained accuracy while bent to a 5 mm radius curve. Throughput varied by a few percentage points, but overall, it handled flexing like a champ. This marks a significant upgrade over previous bendable chips, which could only be tested while resting on their original wafers.
This isn't the first time someone has attempted to create a bendable PCB. In August, an enterprising engineer gave the classic Arduino Uno board a flexible makeover, calling it the "Flexduino." That project incorporated rigid components onto a flexible PCB; Flex-RV takes it a step further – the integrated circuit on the board can also twist and contort.
The full details were published in the journal Nature on September 25.