Lab-grown human minihearts I was surprised to watch a video of vibrating lab-grown human minihearts. They are very small in size just like seasame seeds. It seems they are real hearts. You can also watch the video here https://www.sciencemag.org/news/2021/05/lab-grown-minihearts-beat-real-thing These are first time created in lab. Their beating chambers can be clearly seen in the video. I took a snapshot of these minihearts.