How does inventor intent affect experimental use in patent law?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

Inventor intent is crucial in determining whether an activity qualifies as experimental use. However, subjective intent alone is not sufficient. The MPEP states: “When sales are made in an ordinary commercial environment and the goods are placed outside the inventor’s control, an inventor’s secretly held subjective intent to ‘experiment,’ even if true, is unavailing without objective evidence to support the contention.” (MPEP 2133.03(e)(2))

Objective evidence of experimental intent is necessary, especially when the invention is sold or used in a commercial context. The customer must be made aware of the experimental nature of the use or sale.