Physical distancing and isolation measures adopted worldwide to contain the spread of the COVID-19 pandemic [1] provide an unprecedented opportunity for social robots to be implemented in real settings. The critical role that robots could play in public health during disaster situations has long been highlighted [2] , [3] . Noticeably, applying physical distancing is not always a valid option and, when it cannot be guaranteed, it can lead to devastating consequences. This is particularly problematic in the healthcare sector. It is estimated that healthcare workers represent higher than 25% of all diagnosed cases of COVID-19 in some countries [4] . Social robots can act safely in an environment that has become momentarily hazardous to human beings. These robots could be decisive to minimize intrahospital transmissions by performing functions of monitoring or facilitating teleoperation to connect doctors with patients [5] . Additionally, there is empirical evidence that isolation measures, quarantines, and lockdowns have a serious impact on mental health and psychological well-being [6] , [7] . Social robots could also contribute to palliate mental health issues and promote well-being during this period [3] , [5] .
The present study examines the implementation of social robots in real settings during the COVID-19 pandemic. Social robots are those that interact with humans by following the behavioral norms expected by the people with whom they intended to interact [8] . For a robot to be social, it needs to present specific communicative capabilities and provide social cues towards its human interaction partners to support social interaction [9] . While there is ample debate regarding what characteristics should define specifically a social robot, for the purposes of the present study, the most relevant aspect to characterize a social robot is the consideration of it being specifically designed to interact with humans and in human physical environments [10] .
The aim of the study is to provide an in-depth picture of social robot implementation in the society during the pandemic. Specifically, the study examines the areas and sectors where social robots are being implemented, the roles being fulfilled, the specific tasks being performed, and the robot models being adopted. For that, we traced back and analyzed 195 experiences with social robots worldwide that have been implemented during the COVID-19 pandemic in real settings.
Following [11] we propose three strategic roles that social robots can fulfill to facilitate physical distancing as well as to reduce the drawbacks of isolation during the pandemic. First, to act as a liaison in tasks that require human-human interaction. Second, to act as a safeguard to ensure contagion risk-free environments. Third, to act as well-being coaches by providing therapeutic and entertaining functions for quarantined patients.
Data collection was performed through documentary research, following the method used in [12] . A strategic non-probabilistic sample was used due to the large amount of experiences and the impossibility to quantify all of them on a global scale [12] . The data was obtained between March and June 2020.
Documentary sources were consulted to extract the largest number possible of experiences. The main sources included mainstream and specialized media outlets, technology blogs, robot developers' and robot suppliers' official websites and social media accounts, research papers and reports, study cases published on corporative websites, and national and international robotics organizations websites and reports. For each experience that was identified, as many sources as possible were further localized to contrast information. In total, more than 1.000 documentary sources were examined. In order to include a case in the study, the following criteria were considered:
• Temporality: Only experiences that specifically mentioned being implemented in response to the COVID-19 pandemic were included. • Sociability: Only robots specifically designed to interact with humans and in human physical environments were considered. Non-social robots implemented for COVID-19 related activities were excluded. • Embodiment: Only robots with a physical body were included. • Communication: Only robots that exhibited at least a minimum capability to interact with humans using verbal and/or non-verbal communication, and/or social cues were included. • Autonomy: Only autonomous and semi-autonomous robots were included.
Note: This work is currently under submission. This version of the manuscript has not been peer-reviewed.
Cite as: Aymerich-Franch, L., & Ferrer, I. (2020). The implementation of social robots during the COVID-19 pandemic. ArXiv preprint. ArXiv:2007.03941.
• Movement and navigation: Only robots with movement capacity through gesturing or/and autonomous navigation were included. • Geography: Worldwide A database was created with all the experiences that met the inclusion criteria. Each experience was classified according to the following variables: social robot name, manufacturer, sector/area of implementation, country where the experience took or is taking place, specific tasks performed by the social robot, and institution that implemented the social robot.
The final database contained 195 experiences of social robot implementations in real settings that met the inclusion criteria. Some exceptions to the communication, autonomy, and movement and navigation criteria were made to include some teleoperated machines with robotic appearances identified as robots in the documentary sources. These exceptions were made when the robot represented the only experience that we were able to localize in a country or when the robot performed a function that was not previously included in the database through other robots.
In total, 66 different social robots were identified among the 195 experiences analyzed. The robots that were most recurrent in these experiences were Temi -Robotemi (27), James -Zorabots (13), Pepper -Softbank (10), Greetbot -OrionStar (8), Cruzr -Ubtech (7), and Starship -Starship (7).
The experiences retained in the database were from 35 different countries. The countries in which we identified a major number of experiences were China (56), USA (24), Thailand (20), Belgium (14) , Hong Kong (13), India (10), and The Netherlands (5).
By sector and area, the experiences were implemented in hospitals (104), nursing homes (24), transportation (13) , schools and universities (9), airports (8), hotels (8) , public sector, in places such as parks or streets (8), restaurants (6), office buildings (5), shopping malls (5), stores (3), and highway checkpoints (1).
The specific functions performed by the robots were classified within the three main roles of liaison, safeguard, and well-being coaches proposed in [11] . In most experiences (151), the robots performed multiple functions. Also, the capacity of verbally greet people, which generally complemented other functions, was identified in 94 cases.
The robots that were able to perform the largest number of functions were Cruzr (Ubtech), Pepper (Softbank), Temi (Robotemi), Greetbot (OrionStar), Sanbot (Qihan Technology), and Promobot (Promobot). Only 10 robots were used for a single function, which was either delivery or disinfection.
The liaison role included all functions related to using social robots to act as a link between humans with the aim of minimizing human-human direct contact. Functions associated with the liaison role have become particularly widespread as a result of the pandemic. In particular, 162 of the 195 Note: This work is currently under submission. This version of the manuscript has not been peer-reviewed.
Cite as: Aymerich-Franch, L., & Ferrer, I. (2020). The implementation of social robots during the COVID-19 pandemic. ArXiv preprint. ArXiv:2007.03941. experiences we analyzed implemented social robots to perform at least one function that can be related to the liaison role. Interestingly, functions that were not particularly valued before such as the possibility to bring food to patients have now become of major importance as they facilitate physical distancing between patients and staff. The following functions were identified in relation to this role:
A total of 42 experiences utilized social robots for receptionist-related tasks. In particular, receptionist social robots develop tasks related to patient or customer registration upon arrival, contactless check-ins/outs, book appointments, providing indications, prepare and print prescriptions, or translate information in different languages. Receptionist robots tend to present anthropomorphic features, humanoid or semi-humanoid shapes, and verbal interaction capabilities. Examples of robots that are used for these functions are Cruzr (Ubtech), Pepper (Softbank), Mitra and Mitri (Invento Robotics), Mini Ada (Akin Robotics), and GreetBot (OrionStar). Most of these robots are found at the reception of hospitals. Some experiences were also in hotels, to checkin/out patients in isolation, or in airports, restaurants, stores, office buildings, and shopping malls, to provide indications and guide visitors and customers to specific areas.
Robots that perform COVID-19 pre-diagnosis functions in hospitals represented a total of 18 experiences. The robots are able to make pre-diagnosis assessing patient symptoms through questionnaires and thermal screenings. If the patients exhibit some coronavirus related symptoms, the robot redirects them towards a telepresence consultation or medical staff equipped with personal protective equipment. We also identified three cases of robots that perform COVID-19 pre-diagnosis in a public space (Times Square), a shopping mall, and an airport. The social robots in these spaces also conduct pre-diagnosis through temperature checks and questionnaires. This function works in combination with the function of personalized advice (see Safety Advice). Examples of robots used for this task are Mitri and Mitra (Invento Robotics), Promobot (Promobot), and GreetBot (OrionStar). Most experiences (11) of robots habilitated for prediagnosis functions were located in China.
Providing information was a function available in 37 of the experiences analyzed. The information the robots offer can either be general or personalized. As an example of general information, robots can inform about schedules or offer promotions in shops. When the patient or customer interacts with the robot and asks for a specific question, the robot can offer personalized information such as the specific room where to go for taking a test in a hospital or finding the boarding gate for travelers in airports and accompany them. Robots develop this function in hospitals, but also in stores, hotels, restaurants, universities, airports, and nursing homes. Examples include Medical Service Robot (TMI Robotics), Smart Service Robot (Xiaoben Intelligence), and Pari 2.0 (Paaila Technology).
Note: This work is currently under submission. This version of the manuscript has not been peer-reviewed.
Cite as: Aymerich-Franch, L., & Ferrer, I. (2020). The implementation of social robots during the COVID-19 pandemic. ArXiv preprint. ArXiv:2007.03941.
One of the most widespread functions during the COVID-19 crisis is telepresence (83 experiences). Robots are equipped with a camera and a screen that communicates patients in hospitals or residents in nursing homes with medical staff and relatives. Through this function, patients can get a remote diagnosis after interacting with a doctor or request medical assistance. Telepresence robots are found mostly in hospitals and nursing homes. They have occasionally been used by schools and universities during the pandemic as well, for functions such as graduation ceremonies. Some examples of robots with telepresence functions are James (Zorabots), Temi (Robotemi), Vita (InTouch Health), Cutii (Careclever), and Ninja (Chulalongkorn University).
In 49 of the experiences, robots performed patient monitoring functions. This function is mostly found in hospitals and, occasionally, in nursing homes or private homes. Monitoring functions include measuring body temperature, blood pressure, oxygen saturation, observe patients' routines and report exceptional changes to caregivers. Some of these robots are also equipped with cameras and sensors that allow families or caregivers to remotely monitor the patient, transmit information and images to nurse stations and store this information into the patient medical record, or keep track of medical adherence. Examples include Sanbot (Quihan Technology), Cruzr (Ubtech), James (Zorabots), Cutii (Careclever), Vita (InTouch Health), and Ninja (Chulalongkorn University).
Transportation and delivery is one of the functions that has shown a largest spread as a result of the pandemic. Ninety-four experiences and 36 different types of robots were identified to carry out this function either exclusively or in combination with other functions. The delivery function is also widespread among robots that do not present social features, which were not included in the sample. There are two main groups of delivery robots: those utilized outdoors and those that perform their activity indoors.
Delivery robots in outdoor scenarios have experienced a notable expansion during the lockdown periods. Some specific areas in California [13] and China [14] eased circulation regulations for these robots during the pandemic, which facilitated their adoption. These robots present mostly a functional design. Some social features are included to facilitate communication with pedestrians and package receivers. For instance, lights that suggest eyes are used as a form to indicate that the robot will change direction (Serve by Postmates) or a thumbs-up can be used to order the robot to open or close its doors (R2 by Nuro). Some delivery robots have additionally been equipped with disinfection functions during the pandemic. These robots are used by e-commerce platforms, delivery companies, restaurants and grocery stores in particular neighborhoods and in university campuses as well as to deliver sanitary supplies to healthcare facilities. Kiwibot (Kiwibot), Starship (Starship), RoboPony (Zhen Robotics), R2 (Nuro), and Neolix ADV (Neolix) are examples of outdoor delivery robots.
We identify two main types of robots that perform indoor object delivery. One, robots with an essentially functional design, such as Pudu (Pudu Robotics), Peanut (Keenon Robotics), TUG (Aethon), Hospi (Panasonic), or Run (Yunji Technology). These robots are implemented in hospitals and hotels with quarantined guests to transport medication, linens, meals, medical supplies, and documents. Some can also open and close doors, take elevators, transport heavy objects, store medical waste, or disinfect themselves. Two, robots that present more social features and humanoid or semi-humanoid shapes. These robots are utilized in reception areas of hospitals, nursing homes, office buildings, shopping malls, and airports to distribute masks and sanitizer to visitors. Some of these robots were initially designed for other functions, such as waiter robots, and some have just been added a tray and are now utilized to deliver objects to patients as an additional function. Examples include Ani (Asimov Robotics), Amy (Pangolin Robotics), Zafi (Propeller Technologies), Sona 2.5 (Club First), Temi (Robotemi), or Sunbot (Siasun Robot and Automation).
The safeguard role includes all functions related to ensuring risk-free environments. Safeguard functions specifically adapted to the situation of the pandemic have appeared during this period. Of 195 experiences, 118 have implemented social robots to perform at least one function that can be related to the safeguard role. The following functions were identified in relation to this role:
Of the sample, 66 experiences use robots to provide safety advice during the pandemic. We distinguish two sub-types of functions within this group: general (47 cases) and personalized (19 cases) advice. General advice includes promoting safety measures, recalling guidelines and making recommendations about how to behave in specific places. This function works essentially as a public announcement. Robots offering general advice are found in hospitals, and to a lesser extent, also in airports, public places, shopping malls, schools and universities, office buildings, grocery stores, highways, and hotels. Examples include Sanbot (Qihan Technology), Smart Service Robot (Xiaoben Intelligence), and Ani (Asimov Robotics). Personalized advice can be offered by the robot after completing a pre-diagnosis function (see Pre-diagnosis). If symptoms are identified, the robot advises to seek for medical assistance. These robots are principally located in hospitals, but some experiences are also found in public places. Cruzr (Ubtech), Promobot (Promobot), Mitra and Mitri (Invento Robotics), Medical Service Robot (TMI Robotics), and Pepper (Softbank) are some examples of robots that can offer personalized advice.
Tasks related to enforcing COVID-19 protective measures were identified in 51 experiences. Rather than informing, these robots are particularly deployed to enforce safety measures either in one to one security scans or among crowds. These robots are able to detect if people wear masks, measure body temperature to identify if someone might have a fever or detect if physical distance is maintained. When there is a safety concern regarding these aspects, the robot can take actions such as asking the person to wear a mask, keep physical distancing, or ban entrance to an indoor space. These robots are principally found at the entrance door of hospitals, but also at the entrance of nursing homes, shopping malls, grocery stores, hotels, restaurants, schools and universities, and office buildings. They can also be found patrolling airports, outdoor public spaces, or in highway checkpoints. Examples include Cruzr (Ubtech), Spot (Boston Dynamics), Dinsow (CT Asia Robotics), Aimbot (Ubtech), Temi (Robotemi), Promobot (Promobot), or 5G Huawei robot (Huawei/LIWEST).
Surveillance functions aimed at preventing the spread of the virus were identified in 42 experiences. Robots can be equipped with regular and thermal cameras, lights, speakers, microphones, real-time transmission, and camera recording. These robots can be found patrolling outdoors or indoors. They are either connected to security staff who can communicate through it or programmed to take action when a risk is detected (see Protective Measure Enforcement). In public places, they can be found in parks, parking lots, and busy areas in cities. Robots typically deployed in outdoor spaces are ASR (KnightScope), O-R3 (Otsaw Digital), Atris (Ubtech), PGuard (Enova Robotics), Outdoor Inspection Robot (Hangzhou Guochen Robot Technology), or Spot (Boston Dynamics). Indoors, they can be found in hospitals, schools and universities, shopping malls, airports, nursing homes, restaurants, and office buildings, with robots such as Ainbot (Ubtech) or Temi (Robotemi).
Disinfection robots have experienced a notable expansion during the pandemic. Most of these robots tend to be industrial (and therefore were excluded). Thirty-seven experiences of disinfection robots that present at least a minimal social component were identified. We distinguish two subtypes. One (12 cases), disinfection robots specifically built for this purpose. They have a functional design and present only minimal social features, such as verbal warnings. These robots are mostly found in hospitals and some also in airports. Examples are the UVD Robot (Blue Ocean) and the Intelligent Disinfection Robot (TMI Robotics). Two (25 cases), robots that have added this function during the pandemic and also develop other functions (e.g. surveillance, transportation). Principally, they incorporate a spray to potentially disinfect during navigation. These robots are found in hospitals, schools and universities, restaurants, public places, and office buildings. Examples are Temi (Robotemi), Atris and Aimbot (Ubtech), KiwiBot (KiwiBot), and Neolix ADV (Neolix).
The well-being coach role includes all functions related to preserving physical and psychological well-being. A total of 63 experiences included at least one function related to this role. Overall, the potential of social robots to act as well-being coaches during the pandemic remains underdeveloped as the functions belonging to this role have rarely been specifically adapted to the situation of the pandemic. The following functions were identified in relation to the well-being coach role:
Thirty-eight experiences used robots to offer company and comfort to isolated persons. Robots provide verbal interaction to give basic and motivational conversation. Robots can also express and interpret emotions, have physical contact with the patient, or walk with them. These interactions contribute to emotional support and can also help reduce anxiety during the isolation period. More than half of these experiences were found in hospitals and a significant number also in nursing homes. There were a few experiences in hotels with quarantined guests and at universities to emotionally support students during the outbreak. Examples are Sanbot (Qihan Technology), XR-1 (INNFOS), Pepper (Softbank), Temi (Robotemi), ElliQ (Intuition Robotics), Cutii (Careclever), and Dinsow (CT Asia Robotics).
Robots for entertainment (45 experiences) and edutainment (8 cases) present a strong social component and are generally humanoid or semi-humanoid. Entertainment functions include dancing, singing, playing games, taking and sharing photos with contacts, navigating on the internet, reading news, displaying photos and videos on screen, telling jokes and stories. Edutainment functions involve brain-training exercises like dictation, reading, or playing memory games. Most experiences are deployed in nursing homes and hospitals. Some scattered experiences were located in shopping malls, airports, hotels, office buildings, and restaurants. Examples of robots deployed for these purposes are Cruzr (Ubtech), Sanbot (Qihan Technology), Pepper (Softbank), ElliQ (Intuition Robotics), and Temi (Robotemi).
Robots that perform medical and wellbeing adherence functions by reminding about taking the prescribed medication, appointments, or engaging in healthy habits were identified in eight experiences. These robots generally perform other functions such as monitoring, entertainment, providing general information like news or weather, or telepresence (see these functions above). Experiences are found principally in nursing homes and, to a lesser extent, also in hospitals. Examples of robots used for adherence are Pepper (Softbank), Temi (Robotemi), ElliQ (Intuition Robotics), Dasomi (Wonderful Platform), and Dinsow (CT Asia Robotics).
Social robots that instruct physical exercise, relaxation techniques, dancing, and yoga to patients, residents, or staff in hospitals and nursing homes during the coronavirus outbreak were identified in eight experiences. These robots either perform the movements with their own body or show them on a screen. Examples of robots used for this function are Sanbot (Qihan Technology), XR-1 (INNFOS), Pepper (Softbank), Temi (Robotemi), and Cutii (Careclever).
Overall, we identified a clear resurgence and expansion of social robots in real settings as a result of the pandemic. The social robots' capacity to perform the roles of liaison, safeguard, and wellbeing coach, directly associated with the needs of facilitating physical distance and palliate the effects of isolation, have been key to the renaissance of these robots during this period.
Social robots are developing a particularly outstanding role in hospitals supporting staff, where they contribute to reduce the workload and ensure the safety of the healthcare personnel performing functions associated with receptionist, pre-diagnosis, food delivery, telepresence, or monitoring, among others. They have also gained acceptance as social companions to palliate the effects of isolation, especially in nursing homes. In outdoor and public spaces, these robots have also found an opportunity to develop functions aimed at minimizing the spread of the virus, such as disinfection, delivery, surveillance, or protective measure enforcement.
The companies that develop social robots have quickly spotted the opportunity presented to this industry as a result of the sanitary crisis and have implemented marketing strategies to promote their robots accordingly. Several companies have also offered their robots at zero cost to hospitals, nursing homes, and to elderly people living alone to help fight the pandemic and promote their robots for this purpose. These actions have contributed to generate publicity. Additionally, some public research initiatives, especially in developing countries where robotization is still not largely implemented, have also developed their own robots ad hoc to support healthcare workers during the coronavirus outbreak. In general, press releases tend to be positive towards initiatives of social robot implementation for fighting the pandemic and suggest that social robots have gained larger social acceptance during the pandemic as well.
An aspect to highlight is that most functions that we identified were technically available before the pandemic. However, the relevance of these functions is now boosted due to the needs brought by the sanitary crisis and are now specifically adapted to a situation that demands physical distancing and isolation. This adaptation is particularly visible in the functions associated with the roles of liaison and safeguard. Robots are specifically programmed to detect aspects such as whether people wear masks or keep physical distance. Robots have also been equipped with technologies that are particularly meaningful during the outbreak such as temperature measurement or surface disinfection. Some functions such as being able to transport food in hospitals, which were previously not particularly regarded as crucial, have now gained more relevance as they help minimize human-human contact. Finally, the functions associated with well-being coach have not experienced a major adaptation to the situation and there is clear room for improvement in the field of social robots that can provide phycological aid to support more effectively patients under isolation during the pandemic.