The phrase "are designed solely" is correct and usable in written English.
It can be used to indicate that something is created or intended for one specific purpose without any other considerations.
Example: "These tools are designed solely for professional use, ensuring the highest quality and performance."
Alternatives: "are intended exclusively" or "are made only for".
These arguments are designed solely to give Congress more opportunities to stop financial regulation.
"The decision suggests that there are at least some financial transactions that are permissible even though they are designed solely to obtain tax benefits," Mr. Hariton said.
"Claims chasers don't like our terms and conditions, because they are designed solely to protect our customers, and ensure they receive 100% of the compensation they are due".
The implementation is based on a server-client model where all state information is held by the servers, while clients are designed solely as computational units.
Many enzymes have active sites that are designed solely to facilitate the transfer of an H atom from a substrate to another molecule.
Supporters of such laws argue that they safeguard the integrity of elections; opponents say they are unduly burdensome, and are designed solely to make it harder to register new voters.Similar arguments have been used to support and attack laws requiring voters to show government-approved photo-ID in order to vote.
They were proud, purist exercises in engineering, in which every component was designed solely to fulfill its designated function of producing a delicious cup of espresso topped with bubbling crema.
North Korean officials have said the launching is designed solely to push a satellite into orbit.
This type of building is designed solely to afford protection from the weather, mainly rain.
There is no reason to think that higher education was designed solely for the post-pubescent adolescent.
