The proliferation of mobile devices is something of a double-edged sword for manufacturers. On one hand, Apple once again beat sales expectations in its most recent fiscal quarter, but on the other, the enormous demand is rapidly depleting global reserves of the precious metals needed to build the touchscreens common to every smartphone and tablet.
At particular risk is the supply of indium, which makes up over two thirds of the conductive coating that gives mobile displays their touch sensitivity and could run out within a decade at the current rate of consumption. Until then, manufacturers are faced with the prospect of widening double-digit price hikes every year, but that death spiral may be cut short soon if Samsung has its way.
What you see here is an experimental alternative to traditional indium-tin-oxide coating that made its debut in one of the latest of the mobile giant’s patent filings to have reached their disclosure date. It’s a mesh of electrodes based on a combination of silver, aluminum, chrome, nickel, copper and a metal called molybdenum commonly used in high-strength steel alloys.
The special pattern in which the thin conductive threads are arranged allows the touch-sensitive matrix to be fabbed at the same etching rate as the less granular supporting material below, an approach that makes manufacturing easier and thus more economic at the same stroke. But most importantly, it removes the risk of inconsistencies between the layers interrupting the circuit.
The two charts attached to the filing demonstrate the benefits. Figure 8A shows how the conductive threads grow thinner and more fragile towards the supporting lower layer in a traditional setup, while Figure 8B represents the mesh arrangement, which is the exact opposite. As a result, future Samsung devices that will incorporate the technology should easily match the reliability of current touchpads once indium stops being viable.