The development of semiconductor electronics, in particular silicon-based integrated circuits (IC), revolutionized our civilization in the twentieth century. The fourth container is devoted mainly to Si-based objects made by the same type of technology as used for IC fabrication. Examples of microdevices include: MEMS accelerometers (miniature sensors in everyday use in mobile devices, cars, planes, various industrial applications, etc.), a quadrant photodiode for detection of infrared radiation and an ionizing radiation (alpha particle) detector for the transactinide elements. This box also contains a sample of quartz sand - the basic raw material for all these products, together with a piece of bulk silicon wafer, being the substrate used for IC and MEMS fabrication.