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 9MHz at low supply voltages (∼4V), and the differential amplifiers show good performance and voltage gains of 1.3 for 500mV 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.