A more thorough explanation:

Undue experimentation is a term used in patents to describe an unreasonable amount of research and testing that would be required for a person skilled in the appropriate field to make and work an invention from the patent application. If undue experimentation is required, the application fails the embodiment requirement of 35 USCA § 112.

The Wands test is a judicial test used to determine whether a patent application's specification teaches one skilled in the art how to make and work the claimed invention. The test takes into account eight factors:

1. How much experimentation would be needed
2. How much guidance is given
3. Whether there is a working example
4. The nature of the invention
5. The state of the prior art
6. The level of skill of those in the art
7. How predictable or unpredictable the art is
8. The breadth of the claims

The factors are illustrative rather than mandatory.

Suppose a patent application claims a new type of battery that can last for 100 years. However, the application does not provide any working examples or guidance on how to make the battery. A person skilled in the art would need to conduct extensive research and testing to make and work the battery, which would be considered undue experimentation. Therefore, the application would fail the embodiment requirement of 35 USCA § 112.