Between 2012 and 2050, the number of Americans age 65 or older is predicted to nearly double from 43.1 million to 83.7 million, according to a U.S. Census report published this month. The U.S. Department of Health and Human Services estimates that the country's graying demographics, combined with greater accessibility to healthcare under the Affordable Care Act, will lead to a rise in demand for care services for the elderly. Who will take care of all these Americans in their twilight years?

Robots.

That's the conclusion more and more engineers, entrepreneurs and governments are coming to on how to deal with aging populations. Universities and startups around the world have already built a few early examples our future mechanical caretakers. Here are six of the robots that may tend to us in old age.

HERB

Developed by researchers at Intel and Carnegie Mellon University, the "Home Exploring Robotic Butler" is exactly that -- a prototype robot butler meant to help the elderly with cooking, cleaning and other household chores. (It achieves the full butler vibe with a bow tie.) Perhaps most impressively, the roboticists have taught HERB one crucial kitchen task: how to twist apart an Oreo.

GiraffPlus

Funded by the European Union, GiraffPlus is a program that puts remote-controlled bots in the homes of elderly patients so that friends and family can have virtual visits. The system, which also comes with sensors outfitted around the home that track where someone is and what they're doing, is being tested with six elderly people in Europe, according to the tech blog Motherboard.

Care-O-bot 3

Developed by the German company Fraunhofer IPA, the Care-O-bot is designed to help those who can't move around their homes live independently. The bot can fetch and carry items to its owner after being beckoned though a smartphone app. Like GiraffPlus, it also offers video conferencing and can also call the police in case of emergency.

Cody

Cody is a robotic nurse designed to give baths to the elderly -- a task that may actually be better for non-humans anyway. The team at the Georgia Institute of Technology pitch their robot, which is programmed to apply gentle pressure while washing a patient, as a solution both to the embarrassment of receiving bathing help from another human as well as to the anticipated increase in demand for nursing services for the elderly.

Paro

Studies have shown that animal companionship is therapeutic for the sick, but what is to be done in care facilities where pets may compromise cleanliness? Enter Paro, the adorable robotic seal that's one of Japan's most popular robots.

In several trials, including ones with nursing home residents in Denmark and with dementia patients in Japan, Paro has provided companionship, lowered stress levels and raised the social-bonding hormone oxytocin, just like a dog would. Paro went on sale in the U.S. in 2009, five years after being introduced in Europe and Asia.

HAL

Don't worry, it's not that HAL.