Regina Dugan, head of Facebook's secretive research lab "Building 8", is leaving the company, just after 18 months at the helm."Today I am announcing that early next year I will be leaving Facebook to focus on building and leading a new endeavour. I will be working with leadership over the next several months to ensure 'Building 8' makes a smooth transition into 2018," the executive posted on Facebook late on Tuesday."This was a difficult decision for me. Together, we have already done so much good work. And there are many people that I will miss, personally and professionally," she added.Facebook recently elevated Andrew "Boz" Bosworth to run all of its hardware projects, including virtual reality (VR) company Oculus' hardware and "Building 8" to develop hardware products.However, the company has not made clear that who will take over Dugan's role in leading 'Building 8'.According to the company, Building 8 is "focussed on building new hardware products to advance our mission of connecting the world. We drive innovation in augmented and virtual reality, artificial intelligence, connectivity and other important breakthrough areas".Before heading to Facebook, Dugan led Google's Advanced Technology and Products team that built things such as modular smartphones and clothes outfitted with micro-sensors. Earlier, she worked as the director of DARPA -- the special research lab that builds new technology for the US military.