An optical mouse uses a beam of light and an optical sensor to detect movement over a surface -- there are no moving parts.

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However, there are problems with longer-term use, as the skin constantly produces new cells, while those at the surface die and are brushed off, meaning a new sensor would need to be attached at least every fortnight.

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This microscopic scale and sensitivity allows the sensor to map a high-resolution image of electrical charge that occurs over the surface of a source material (for example a human finger), when it makes contact with a thin insulating surface (ie a plastic surface).

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The gene produces a molecular sensor on the T cell that is designed to latch on to a telltale protein on the surface of that specific type of cancer.

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