Table 2.

Description of social robots used in reviewed articles.

Robot	Physical appearance and specs	Sensors	User interactivity	Purpose
Paro	Paro is a robotic harp seal, weighing 6 lbs and 22.4 inches long. Paro can be recharged through its “pacifier” battery charger. Its fur is removable, washable, fluffy, and antibacterial. The US Food and Drug Administration has classified Paro as a “biofeedback medical device,” and the platform is not programmable by external users.	Has five kinds of sensors: tactile, light, audition, temperature, and posture sensors, with which it can perceive people and its environment.	He can sense when being touched by its tactile sensor, or when being held by a posture sensor. Can also recognize the direction of voice and words such as its name, greetings, and praise with its audio sensor. His voice imitates a harp seal.	Paro is meant to provide similar comfort as animal therapy for patients in facilities where live animals may present treatment or logistical difficulties. Paro may be used for comfort, companionship, or stress reduction.
Betty	Betty is an individualized, socially-assistive robot, with the technological name Partner Personal Robot PaPeRo. Betty is 15.35 inches tall and weighs about 14 lbs. Betty is programmable by users external to the company.	Betty has audio, touch, movement, and visual sensors; specifically, it is equipped with a camera, microphone, a touch-pad, and speakers.	Voice recognition is the primary modality for interacting with Betty. The robot can also make human-like gestures, has voice recognition capabilities, is mobile, and can be programmed with a person’s preferences (eg, books, games, or music).	Betty may be used for motivation, entertainment, or companionship. The robot is meant to provide human-like interactions and reciprocal engagement, while also providing a calming effect for users.
NAO	NAO is brightly colored with large eyes and humanoid appearance. NAO stands at 22.8 inches tall and weighs 12.1 lbs. Its default walking speed is 0.2 mph. The robot is fully programmable.	It has multiple sensors for touch, sound, speech, and visual recognition. NAO is also capable of movement, with both fall and fall recovery capabilities.	NAO interacts with users via an audio system, often with accompanying movements and lights. It has speech recognition and dialogue with NAO is available in 20 languages.	It has been used in research with children who have developmental disorders or disabilities. NAO is also used for motivation or companionship
Haptic Creature	The Haptic Creature is a comfort robot and was designed based on human-animal interaction models. It is characterized as an expressive animatronic lap-pet (size of a large cat). It is 12.9 inches long and weighs 5.5 lbs. The platform utilizes custom programming that may be available to external programmers upon request.	Includes a 30-item touch dictionary developed from social psychology and human-animal interaction literature. It perceives movement and touch, responding with ear stiffness, modulated breathing, and vibrotactile purring.	Users interact with the Haptic Creature solely through touch, with the robot responding with movement and visual cues to mimic relaxed breathing.	Through touch, it promotes emotional interaction with the user with the aims to reduce anxiety similar to animal assisted therapy. It can also be used for comfort or stress reduction.
CRECA	CRECA stands for “Context Respectful Counseling Agent” and works in conjunction with an on-screen counseling agent avatar. The platform utilizes custom programming that may be available to external programmers upon request	This robot is connected to a computer and microphone to perform speech functions using natural language processing. It can also perform nodding movements.	It can converse with the users, respond to client verbalizations with prompts for continued discussion, and nod its head to validate the user’s responses.	CRECA primarily serves as an educational or motivational robot that can mimic the verbal and non-verbal interactions between counselors and clients