QTC TECHNOLOGY

QTC Material

Introduction to Quantum Tunnelling Composite (QTC)

Quantum Tunnelling Composite (QTC) is a new class of electrically conductive material that has been developed to advance the capability of switching and sensing systems. QTC is a pressure switching and sensing material technology.

QTC is a patented technology developed in the UK by Peratech Limited based on original discoveries by David and Chris Lussey, the company's founders.

First produced in 1996, QTC is a composite material made from metal filler particles combined with an elastomeric binder, typically silicone rubber. The unique method of combining these raw materials results in a composite which exhibits significantly different electrical properties when compared with any other electrically conductive material.

QTC - electrically conductive material

QTC has the unique ability to smoothly change from an electrical insulator to a metal-like conductor when placed under pressure. While in an unstressed state the QTC material is a near-perfect insulator; with any form of deformation the material starts to conduct and with sufficient pressure metallic conductivity levels can be achieved.

Historically, carbon particulates have been used in conductive composites. However, these traditional carbon composites are different in significant ways and these differences make QTC a unique answer to many switching and sensing problems.

The major differences are:

Carbon composites always show some conduction, typically with a resistance of a few thousand ohms, whereas in the unstressed state, QTC can be considered an insulator at 10¹² ohms.
Under pressure, carbon composites can decrease to a few hundred ohms, whereas QTC can reduce to less that 1 ohm.
The deformation required to produce a significant (factor of 10) change in resistance is significantly less for QTC than for carbon composites – QTC is more sensitive.

These differences mean:

QTC can be used as a solid state switch - in the "off" state it is a good insulator and in the "on" state it is as good as a metal conductor.
QTC can be used to detect even very small changes due to compression, tension or other stresses.
QTC devices can carry significant currents allowing for the direct control of loads.

Peratech has introduced new components for switching and sensing applications enabled with QTC for potential uses across a wide range of industries. See examples of potential QTC applications.

QTC can be tailored to suit different force, pressure or touch sensing applications – from sensing feather-light or finger operation to heavy pressure applications.

QTC potential sensing capabilities

▲ Examples of potential sensing capabilities of QTC material

Key benefits of using QTC

QTC is a pressure/force sensing material. It can be easily integrated into existing products to enable force sensing opportunities and solutions.

Product surfaces can be incorporated, coated or impregnated with QTC to impart the properties of force sensing into or onto the host surface.

QTC material can be formed or moulded into virtually any size, thickness or shape, permitting redesign of product interfaces and providing improved ergonomics, aesthetics and user comfort.

QTC is an enabling technology which is simple and reliable to use.

QTC material is durable - it has no moving parts to wear out.

QTC material is mechanically strong.

QTC material can be made to withstand extreme temperatures limits.

QTC material is versatile, both electrically and physically e.g. Its range and sensitivity can be altered. QTC material is also intrinsically safe - the material is a contactless switch, ideal for sparkless operation.

QTC material can be directly interfaced to standard electronic and electrical devices.

QTC material and/or technology can be customised for customer requirements, applications and products.

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