$1m to reinvent the condom
Bill Gates, the world's second-richest man, is offering up to$1-million to anyone who can reinvent the condom.
The Microsoft founder's charitable foundation says that little has been done to use technology to make condoms that are "more pleasurable".
He said doing so would increase their use and help to prevent the spread of sexually transmitted diseases around the world.
The Bill and Melinda Gates Foundation, which aims to improve the lives of the world's poorest, will provide $100000 in start-up costs to the successful maker of a "next-generation condom" and would continue to fund the enterprise up to the value of $1-million.
In a statement the foundation said: "Condoms have been in use for about 400 years yet they have undergone very little technological improvement in the past 50 years.
"Material science and our understanding of neurobiology has undergone a revolutionary transformation in the last decade, yet that knowledge has not been applied to improve the product attributes of one of the most ubiquitous and potentially under-utilised products on earth."
The foundation said it was looking for a design that "significantly preserves or enhances pleasure, in order to improve uptake and regular use."
It added: "The one major drawback to more universal use of male condoms is the lack of perceived incentive for consistent use. The primary drawback from the male perspective is that condoms decrease pleasure as compared to no condom, creating a trade-off that many men find unacceptable.
"Is it possible to develop a product without this stigma, or better, one seen to enhance pleasure? If so, would that product lead to substantial benefits for global health?"
The search for a better condom was launched as part of the foundation's Grand Challenges in Global Health research initiative.
It says annual production of condoms is 15billion each year and there are 750million users.
The foundation's Chris Wilson said: "To overcome health and development problems we need new, game-changing ideas."