If you thought the Raspberry Pi's chip was dinky, well, get a load of the nattily named Texas Instruments MSPM0C1104, said to the world's smallest microcontroller or MCU and measuring a mere 1.38 mm².
Despite the diminutive proportions, which Texas Instruments claims to be 38% smaller than any other MCU, this teensy spec of a chip packs a fully functional Arm 32-bit Cortex-M0+ CPU core running at a towering 24 MHz. It also has 16 KB of flash memory and 1 KB of SRAM.