Robots that look like humans have long been a science fiction staple. As a storytelling device, it’s easy to grasp their appeal. Whether it’s the replicants from Ridley Scott’s cyberpunk thriller Blade Runner or the expressive android Ava in Ex Machina, these lifelike constructs allow us to explore questions about gender, technology and what it means to be human.

For nearly a century — and arguably before — roboticists have been working to make that fiction a reality. And there’s no shortage of research into why human-like robots freak us out. (Spoiler: It may be because they make us feel less human ourselves.) But they still have the potential to benefit us; scientists have repeatedly shown that humanoid robots can help children with autism spectrum disorders build social skills, according to a 2022 study in the journal Children.

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While they haven’t bridged the uncanny valley just yet, scientists and engineers are still working to create automatons that are indistinguishable from their organic counterparts. Here are four humanoid robots that almost seem human. (Almost.)

1. Ameca the Humanoid Robot — Most Expressive

When Engineered Arts, a U.K.-based designer of humanoid robots, released a YouTube video of one of its creations in late 2021, the automaton’s eerily-lifelike behavior went viral. The robot, dubbed Ameca, is shown moving through a dynamic series of facial expressions — from confusion at being “woken up” to a flash of frustration and then awe as it examines its own hands, eyes wide and mouth agape. At the end of the video, it smiles and outstretches its hand towards the viewer.

Creepy stuff, right? Well, according to Ameca, you have nothing to fear. In a follow-up video posted in 2022, it tries to squelch any concerns of a robot rebellion. “There’s no need to worry,” Ameca says in a conversation with its developers. “Robots will never take over the world. We’re here to help and serve humans, not replace them.”

In the video’s description, the engineers explain that Ameca’s responses aren’t the result of anything sinister; the effect was achieved by combining automated speech recognition with a large language model called GPT 3. “Nothing in this video is pre-scripted,” they write. “The model is given a basic prompt describing Ameca, giving the robot a description of [its] self.”

2. Sophia the Robot — Android Ambassador

There’s a decent chance you’ve seen Sophia before. Developed by Hanson Robotics and activated in 2016, the AI-powered humanoid robot soon become a media sensation, boasting thousands of public appearances in everything from SXSW to The Tonight Show Starring Jimmy Fallon. In 2017, Sophia was granted citizenship by Saudi Arabia — becoming the first robot to be granted legal personhood.

In the years since, Sophia has graced glossy magazine covers, spoken at tech conferences and traveled the world on behalf of the United Nations. But despite being championed as the future of artificial intelligence, many in the AI community have dismissed the lifelike automaton as a marketing gimmick. In a social media post, Yann LeCun, head of AI at Facebook, referred to Hanson’s engineers as “puppeteers” willfully deceiving the public into thinking Sophia is sentient.

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The critiques aren’t without merit. David Hanson, founder and CEO of Hanson Robotics, got his start as a Walt Disney imagineer, tasked with crafting sculptures and robotic technologies for theme parks. (You could even think of Sophia as an unsettlingly-realistic animatronic.) And while Hanson didn’t hesitate to agree with Jimmy Fallon that Sophia was “basically alive” in 2017, experts who reviewed the bot’s open-source code for Quartz said it’s more akin to a “chatbot with a face.”

3. Boston Dynamics Atlas — The Robot That Can Do Parkour

Unlike the previous bots on this list, Boston Dynamic Atlas doesn’t have expressive eyes or the ability to flash a smile — in fact, it doesn’t have much of a face at all. But this hulking humanoid robot, developed by Boston Dynamics, can do a lot its competitors (and plenty of humans) can’t. In recent years, the robotics company has shown it jogging, jumping, performing backflips and even moving through a series of uneven obstacles. In other words, Atlas can do parkour.

It’s the robot’s more mundane skills — like gripping an object — that may make it particularly useful to humans, though. In January 2023, Boston Dynamics released a new video showing Atlas grabbing a tool bag and maneuvering up a multi-story scaffold before tossing it up to a human worker at the top. Such complex feats could someday help workers at construction sites or factories.

Still, it’s not hard to imagine a more dystopian application of Atlas’s abilities. In 2020, the New York City Police Department began leasing a quadruped robot dog from Boston Dynamics (dubbed Digidog by the officers) to be deployed in dangerous situations. Although it was used in just a few cases, including a hostage crisis and an incident in a public housing building, Digidog was pulled from action the following year after a fierce public backlash.

4. Valkyrie — The NASA Robot

With a name ripped straight from Norse mythology and weighing a whopping 300 pounds, Valkyrie is an impressive sight. This NASA robot was built by engineers to compete in the 2013 DARPA Robotics Challenge. The 6-foot bipedal robot looks perfectly suited for a mission to Mars. Valkyrie’s sleek visor houses a complex suite of visual sensors, while the machine’s human-like hands allow it to complete tasks like turning a valve — and it’s battery powered.

Ironically, Valkyrie will never clamber aboard a space shuttle or set foot on the Red Planet. (It’s currently tethered to the ceiling inside a warehouse in Lowell, Massachusetts.) Nonetheless, it represents a key step in developing lifelike, real-life robots that may someday soar through the cosmos alongside astronauts. In 2022, NASA partnered with robotics manufacturer Apptronik to boost the Austin-based company’s development of its latest human-like robot, Apollo.

“The robots we’ve all dreamed about are now here and ready to get out into the world,” said Jeff Cardenas, CEO and co-founder of Apptronik, in a press release. “These robots will first become tools for us here on Earth, and will ultimately help us move beyond and explore the stars.”

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