Consumer electronics company Philips has developed a pen that can help reveal a writer's true emotional state during writing.
Sensors in the pen help perform this task by detecting physiological factors like heartbeat, blood pressure, skin temperature, and finger pressure.
A small actuator has been installed in the pen, which can change the properties of the line it traces out by switching inks and modifying the shape of the writing tip.
The writer's emotional state is then determined by a built-in chip, which changes the colour and quality of the trace accordingly.
"Signatures are currently always the same, yet some documents will be signed with enthusiasm, others possibly with hesitation. Having a recording of this could be useful for historical reasons," New Scientist magazine quoted Philips as saying.
Just in case, a writer does not want his/her true feelings expressed, an on-off switch on the pen may be used to inactivate this function.