Electronics that are capable of destroying themselves, on demand and in a harmless way, might provide the ultimate form of data security. This paper presents materials and device architectures for triggered destruction of conventional microelectronic systems by means of microfluidic chemical etching of the constituent materials, including silicon, silicon dioxide, and metals (e.g., aluminum). Demonstrations in an array of home-built metal-oxide-semiconductor field-effect transistors that exploit ultrathin sheets of monocrystalline silicon and in radio-frequency identification devices illustrate the utility of the approaches.