Originally published in The Economist.

Condom technology

Sheathing Cupid’s arrow

The oldest artificial contraceptive may be ripe for a makeover

Feb 15th 2014 | BOSTON | From the print edition

THEY have been made of tortoiseshell and horn. They have been made of the finest silk and the coarsest leather. They have been made of pigs’ bladders and sheep’s intestines. They have been made of rubber (natural and synthetic). They have been made of plastic. But none of these has quite fitted the bill. Condoms, though 15 billion are manufactured each year, and 750m couples use them, are not, when push comes to shove, that popular. In truth, they are awkward passion-killers that have a disturbing tendency to pop off at inconvenient moments.

Build a better condom, then, and maybe the world will beat a path to your door. That, anyway, is what a select band of researchers in laboratories around the world hope will happen. So does Bill Gates, whose foundation is backing some of these efforts with grants of $100,000 apiece as seed money, and the promise of up to $1m more if the initial experimentation comes good.

Mr Gates’s foundation, the biggest non-governmental source of cash for global health, is interested in condoms for the same reasons most users are. Not only do they prevent unwanted pregnancies, they also stop the transmission of venereal infections—particularly HIV. The search for a better condom, then, looks like a public good as well as a private one. And there is no shortage of ideas about how to do it. When the Gates Foundation picked the first 11 winners, in November 2013, it was able to choose from among 812 proposals. The winners of a second round, currently being judged, and emphasising the hitherto neglected field of “femidoms” (those worn by women rather than men), will be announced in May.

Cap this!

One of the most intriguing approaches to building a better condom is to reinforce the latex that modern prophylactics are made from with graphene. This material, composed of atom-thick sheets of carbon, is one of the strongest known. Its thickness (or, rather, lack of it) and its strength make it an obvious starting point for something that is supposed to be permeable to pleasure, but not to anything else.

One of the groups looking at graphene-reinforced contraception is led by Aravind Vijayaraghavan of the University of Manchester, in Britain. This is the institution where, a decade ago, graphene was discovered. Dr Vijayaraghavan’s team plans to make a thin but tough, tear-resistant membrane, suitable for condoms, by mixing it with latex or polyurethane.

A second group that is interested in graphene, run by Lakshminarayanan Ragupathy of HLL Lifecare, India’s largest condom-maker, hopes to go further. Dr Ragupathy, too, intends mixing the carbon sheets with latex to create a strong composite material. But he also proposes to adsorb chemicals such as spermicides, antiviral agents and even flavourings onto the graphene. Some of these are already used in condoms, but at the moment they have only the smooth surface of the latex to stick to. Add graphene, and that surface becomes much rougher (and its area much larger) at a microscopic level, meaning more chemicals can be retained on it.

Graphene is not, however, the only alternative material being suggested for the condom industry. Mark McGlothlin, boss of Apex Medical Technologies, in San Diego, plans to borrow from the past rather than looking to the future, by using collagen, the stretchy protein that made guts so suitable for use as condoms in olden days. He intends to extract his collagen from cows’ tendons and fish skins rather than intestines, and will break it down and reassemble it in a way that eliminates offensive odours, imperfections and pores—for, while the pores in natural collagen are too small to let sperm through, they are big enough to pass viruses.

Making condoms more effective is one thing. But it will be of little use if they act as a barrier to sensation as well as sperm. The usual way to try to increase sensitivity is to make their material thinner. But Patrick Kiser of Northwestern University, in Illinois, plans to tackle the problem in a different way. Though he is cagey about the details, he says his group will make its condoms out of polymers which mimic the feel of the mucosal tissue encountered during unprotected intercourse.

Karen Buch and Ducksoo Kim, of Boston Medical Centre, are also concerned with how condoms feel in action. They are trying to create a sheath which lubricates itself when in contact with water. That would eliminate the unpleasant oil-based lubricants condoms currently use. To do this, the two researchers have turned to the fashionable field of nanotechnology. They propose coating their condoms with tiny particles of a polymer that binds tightly to water—an arrangement which forms what is known as a hydrogel. This, they hope, will reduce friction and produce a smooth, gliding sensation for users.

In Los Angeles, meanwhile, Ron Frezieres of the California Family Health Council, a charity, plans to fashion condoms from polyethylene, which is stronger than latex (so condoms made from it can be a fifth of the thickness of present-day ones) and does not provoke allergic reactions in the way that rubber sometimes does. Polyethylene’s disadvantage is that it does not have latex’s elasticity, which holds things in place at the crucial moment. But Mr Frezieres, who has been testing and developing condoms for 30 years, claims this should not matter because a condom made of the right sort of polyethylene will cling like shrink-wrap. Moreover, his device includes special tabs that allow it to be pulled on like a sock. That would be harder to do if it were elastic, and thus just stretched when pulled.

How to get the thing on easily is also the concern of Willem van Rensburg of Kimbranox, in Stellenbosch, South Africa. He and his team are working on the “Rapidom”, which can be deployed “with one motion, thereby minimising interruption,” as the Gates Foundation coyly puts it. The Rapidom is a condom in a packet so organised that, instead of having to be ripped open and the contents struggled with in the heat of the moment, it can be grasped on either side and pulled apart, unrolling what is inside in a controlled way.

Once a condom is on, though, there remains the question of preventing it from coming off inopportunely. Benjamin Strutt and his team at Cambridge Design Partnership, a British technology consultancy, are tackling that with a material which, unlike latex, stretches and contracts in one direction (around the penis) more easily than the other (along it). It thus tightens gently during intercourse, and holds itself firmly in place.

Richard Chartoff of the University of Oregon is also tackling the problem of keeping condoms in place. He plans to make them from a polymer with “shape memory” that will, when it reaches body temperature, conform to the contours of a penis and thus provide a custom fit.

Johnny comes marching home

One way or another, then, it looks likely that a better condom is just around the corner. Not everyone, however, thinks the world’s lovers actually will beat a path to its inventor’s door.

One sceptic, a man who has seen it all before, is Jeff Spieler, the United States Agency for International Development’s main condom expert, who began researching the devices in the 1980s. Though he tested many novel designs then, from ones that had ends like ice-cream whirls to those that could be worn inside-out without loss of effectiveness, he says it was hard to come up with something that pleased enough people more than the tried and trusted traditional design did.

Quotidian improvements rather than innovative leaps have actually been the order of the day. Breakage rates, for example (which most users probably regard as the crucial test of a condom’s effectiveness), have fallen without fanfare to 1-2%, down from 11-13% in the 1980s. It may be, therefore, that the innovation condoms really need is not in design, but in marketing.

That is suggested in particular by the different patterns of condom use seen in different parts of the world. According to the Population Reference Bureau, an American think-tank, 20% of married couples in rich countries use condoms, while 18% prefer the pill—and these two methods are the most popular forms of contraception in such places. In poor countries, intrauterine devices and sterilisation are the most popular methods, and the respective figures for condoms and the pill are 4% and 7%. Moreover, the rapidly falling birth rates in most poor countries suggest that, for family planning purposes, radical change is not needed. So the paradox is that if a better condom does emerge from all this effort, it may be enjoyed more by the rich world’s inhabitants than those of the poor world at whom, at least in Mr Gates’s eyes, it is aimed.

This does not mean efforts to develop a better condom are wasted. Though death rates from AIDS are falling, thanks to the wide availability of antiretroviral drugs, HIV is still spreading. In the absence of abstinence, or of complete fidelity, condoms are the best way of fighting that spread. So, though it is not, perhaps, the most romantic of Valentine messages, when the rubber hits the road, anything that makes condoms better and easier to use must surely still be welcome.

From the print edition: Science and technology