Inkjet-patterned titanium oxide memristive junctions connected in series for a threshold indicator

The use of memristive devices can simplify circuit designs and reduce power requirements for low-cost printed electronics. Here memristive metal/oxide/metal junctions were patterned by inkjet printing, and the printed device characteristics were measured to infer ionic and electronic transport parameters such as mobilities and ion distribution. The flux dependence was analyzed for an individual junction as well as for junctions connected in a series. There was continuous dopant redistribution under increasing flux, leading to a peak in conductance. With multiple memristive devices, the circuit conductance was shown to be linearly proportional to the number of junctions placed in the series. The mutable conductance of memristive junctions was utilized to demonstrate a threshold detector, in which printed memristive junctions were connected with a piezo voltage-pulse source and an electrophoretic display output. The memristive circuit would switch the color of display pixels depending on the number of input pulses sensed by the piezo. This demonstration used only passive circuit components and no battery and illustrated the potentials of using memristive elements in printed electronics.