First, there was the vibrating underwear for couples. On Friday, a startup company named Minna said it is in search for backers for its new creation - a couples' vibrator called Limon.

The sex toy, which looks like a pink lime-lemon hybrid, is described as an ultra-powerful bullet vibrator controlled by how hard the user squeezes it.

The vibrator's strength lies in its use of a motor normally used for large sex toys into its lime-sized body. However, what makes the device stand out from other vibrators in the market is its customisable memory that allows the recording and playbacks of vibration levels used previously.

Minna, which believes it has a potential goldmine in the device, said the battery of the Limon vibrator would last between 90 and 180 minutes, chargeable using a USB cable. The vibrator, which comes in teal and pink colours, is waterproof, meaning its safe to use while inside the shower or in the bathtub.

Backers who want to try out the device could donate as low as $25.

Forbes estimated the U.S. vibrator market at $1 billion, twice the size of the condom market, which is about $450 million.

Thus, condom maker Trojan diversified and forayed into the vibrator market with the 2011 release of the Trojan Vibrating Twsiter which has a handle that could be twisted in four different positions. The device costs $60.