By Tim Cole
Digital twins are quickly bringing us closer to better modeling and stress testing factories and supply chains to achieve higher levels of resilience. But there is one factor that is usually ignored: people!
Digital twins are much more than CAD images. They contain and respond to data inputs, transitioning from one state to another. In a manufacturing context, this could be a twin of a machine or production line, into which I input data to simulate what happens under different loads.
Digital twins are already well established in sectors such as manufacturing, where they are used for monitoring, diagnostics and forecasting to optimize equipment performance and utilization, predict equipment failures or determine supply chain inventory, where humans are not a dynamic part of the model. On the other hand, the metaverse allows humans to interact dynamically in environments composed of digital images – e.g., furniture, cars, images of products – but without being able to change the state of these objects. In a Metaverse environment, you can see the physical layout of equipment in its location in the factory – most likely based on a CAD drawing – and walk around it. But we wouldn’t be able to “operate” anything because we’re only looking at CAD images and can’t access or update the data.
Putting a digital twin into a metaverse creates a “metafactory” where people can experience and work with the machines and systems that make up the factory. A metafactory would make digital twins more alive because people are a hugely important aspect of any system. In other words, it’s not really a twin if there are no humans in it.

To map the relationships and connections between people, goods, economies, and societies, we need to develop methods that provide a simulation, prediction, and decision-making environment for solving diverse and complex social problems.
There are few limits to the theoretical possibilities here. The European Space Agency’s Destination Earth project aims to develop an accurate digital model of the Earth to monitor and predict the interaction between natural phenomena and human activities.
But that’s just a start. By combining PLM (product lifecycle management), intelligent healthcare, and the development of other related technologies such as data mining, data fusion analysis, artificial intelligence, especially deep learning, and human informatics, the concept of an augmented digital twin as the basis of the human digital twin (HDT) concept is becoming increasingly possible. It will provide feedback information such as diagnoses, predictions, or other suggestions, and ultimately enable two-way communication between the two. The Augmented Digital Twin model extends the concept of the Digital Twin and can be used to comprehensively describe the relationship between physical space and cyberspace.
The human digital twin will have a number of characteristics:
- Each human in the real world has a corresponding HDT stored in cyberspace. Each of them has a unique index that can be used as an ID and can also be used as an account to log into the HDT. As soon as a person is born, his HDT (assuming that he is a male) is created by a qualified person, who may be a doctor, his parents or other experts in a hospital or other institutions. It will accompany the whole life of the person. The next generations of the child will inherit some of his biological-genetic characteristics. And, of course, he also inherits biological-genetic characteristics from his ancestors.
- Each real person and the corresponding human digital twin would change synchronously. All changes of the person itself will be transferred to cyberspace, and the Human Digital Twin will change accordingly. Some attributes of the real person, such as age and height, will naturally and gradually increase, and at the same time, according to the law of human growth, the Human Digital Twin will also “grow”, which can be corrected by the information coming from its real counterpart.
All kinds of sensor data that can be worn on the body, such as weight, blood pressure, pulse, heart rate, respiration, blood sugar, range of motion and emotional changes, will be sent to the Human Digital Twin through communication technology.
Humans are complex beings and difficult to represent in cyberspace. Modeling, data analysis, and data fusion require much more knowledge than constructing a digital twin.
What else can we accomplish with human digital twins? For one, digital twins with the personality and characteristics of individual humans can respond as if they were the real humans when approached by others in cyberspace. Conversely, if the Digital Twin is allowed to act autonomously, it can also approach others. A meeting between Digital Twins, for example, can be useful for developing group intelligence because it allows you to reach an agreement instantly by mixing a wide range of personalities and expertise without having to consult people in the real world, and you can do things like visualize trends in the group’s thinking in real time.
Using the Digital Twin, you can expand the scope of human activity from the real world to cyberspace. In cyberspace, the Digital Twin behaves as if it were the person himself, which makes it possible to create a powerful personal assistant working on behalf of the real person. The fact that a Digital Twin can be duplicated means that it is also possible to work in multiple locations simultaneously.
Digital twins can also be used to communicate with people who do not currently exist, such as deceased people, to gain knowledge and experience. For example, you can communicate with your past and future self in dialogues that would not be possible in the real world. These dialogues can be used to promote self-knowledge, rediscover yourself, gain ideas, etc., as well as for personal decision-making.

You can also use Digital Twins as an interface in cyberspace. For example, you can create a derivative of your own Digital Twin equipped with skills that you do not possess (e.g., language skills) by exchanging or merging the skills of your own Digital Twin with those of another. You can then use these newly acquired skills in the real world using different devices.
Digital Twin Computing not only consists of entirely new technologies, but also leverages various existing technologies such as hardware, software, networks, and AI and IoT. We need to look at a cross-section of a variety of technical areas to get the big picture. In addition, when using human digital twins, we need to take a close look at non-technical issues such as ethical issues, reliability of simulation results, and privacy protection.
To achieve this, we need the collaboration of experts from different research and technology fields, including social sciences, humanities, natural sciences, applied chemistry, and interdisciplinary fields – either themselves or their Human Digital Twin!