Computer devices (10) that are resistant to contamination by microbes are
provided. The device (such as a keyboard (10), mouse or other computer
device) is treated or manufactured with a photosensitizer compound that
is activated by electromagnetic radiation (16) to provide an
antimicrobial effect. One or more light sources (14; 19) may be utilized
to activate the photosensitizer compound and these may be incorporated
inside or outside of the computer device (10). A laptop computer in which
the electro-magnetic radiation is provided by the display screen (30) so
as to provide an antimicrobial effect to the keyboard (13) is described.