Bendable integrated circuits on plastic substrates by use of printed ribbons of single-crystalline silicon

This letter presents studies of several simple integrated circuits-n-channel metal-oxide semiconductor inverters, five-stage ring oscillators, and differential amplifiers-formed on thin, bendable plastic substrates with printed ribbons of ultrathin single-crystalline silicon as the semiconductor. The inverters exhibit gains as high as 2.5, the ring oscillators operate with oscillation frequencies between 8 and 9 MHz at low supply voltages (similar to 4 V), and the differential amplifiers show good performance and voltage gains of 1.3 for 500 mV input signals. The responses of these systems to bending-induced strains show that relatively moderate changes of individual transistors can be significant for the operation of circuits that incorporate many transistors. (c) 2007 American Institute of Physics.