Wearable Haptics Deepa Mathew University of Tampere Department of Computer Sciences Interactive Technology Seminar: Wearable Haptics December 2008
i University of Tampere Department of Computer Sciences Interactive Technology Deepa Mathew: Wearable Haptics Seminar paper, 15 pages, 3 index December 2008 Touch is one of the most important senses and a crucial factor for a healthy physical and mental development. With the help of haptic technology, that is: technology that interacts with the user through the sense of touch, we are able to apply the sensation of touch with haptic device. The word Haptic means to touch or come in contact with and thus we can just say that haptics deals with the sense of touch. This paper about wearable haptics briefly describes about haptics, the importance of touch and also explores different types of wearable haptics and the implementation of haptics in various forms to help users to feel the sensation of touch for various purposes. Also the use, benefits and challenges of wearable haptics are mentioned in this paper. Key words and terms: Wearable haptics, haptic device, tactile, emotions, touch.
ii Contents 1. Introduction...1 1.1. Importance of touch...10 1.2. Haptic device...10 1.3. Wearable haptics...10 2. Haptic scarf...3 2.1. Challenges with haptic scarf... 10 3. Haptic hug shirt...5 4. Haptic massage therapy...6 5. Haptic garments...7 5.1. Haptic sports garments...10 5.2. Haptic Suit for Improved Human Motor Learning...10 6. Haptic gloves...9 6.1. Haptic glove that enable user to feel panels and switches...10 6.2. Musical haptic gloves...10 7. Summary...11 References...12
1 1. Introduction Touch is one of the five senses and an extremely important sense for humans. The sense of touch allows to feel, perceive and also to interact. Haptic is relating to the sense of touch and a haptic device could stimulate touch. The word Haptic came from the Greek word haptesthai, which means to touch or come in contact with. The Haptic technology refers to the technology of touch that interacts with the user via the sense of touch by applying forces, vibrations and/or motions to the user. This mechanical stimulation is used to mimic real touch and also to create haptic virtual objects. Haptic technology is rapidly gaining popularity in this emerging high-tech world as it can provide the sense of touch in virtual and in real environments. To understand how haptic device work it is important to understand how the sense of touch works on the body. Also the importance of touch needs to be understood to help stimulate haptic feeling on the body in the absence of real human contact (more information below in section 1.1). 1.1. Importance of touch Between 1950 and 1960, Harlow conducted few experiments on monkeys and found that infant rhesus monkeys (which share over 90 percent genes with humans), preferred surrogate mother objects providing contact comfort to those providing nourishment (see Figure 1). These studies established that it was touch and not food that promoted attachment like behaviour. Animal research on touch has extensively documented the benefits of early tactile contact and the consequences of touch deprivation [Harlow, 1950-1960]. Figure 1. Infant monkey with surrogate mother object, (frames covered with a terry cloth surface and bare wire frames featuring a nipple and milk supply)
2 1.2. Haptic device Haptic device is a device that is used to stimulate haptic feeling mechanically. There are several types of Haptic device that are used for different purpose and stimulate different feedbacks. Basically the haptic device use tactile and force feedback to create realistic feeling of touch, but in more advance haptic device even motion and temperature change is used to mimic natural human touch. Like human body, even human touch is a very complex area and due to its complexity it becomes challenging to mimic the natural feeling of touch mechanically but with proper research and technology it could be done. In the later sections more details about wearable haptics are mentioned. 1.3. Wearable haptics Wearable haptic is a haptic device that is worn on the body. It could be in the form of clothes or footwear or even accessories that could be worn on the body. Wearable haptics can be very convenient and also most of the wearable haptic devices are easy to carry around anytime anywhere as it is worn on the body. But apart from its benefits, it has its own challenges too. As it is worn on the body, there are certain limitations that need to be taken into account. For example: The device should not be heavy, also it needs to be comfortable to wear. Apart from the design of wearable haptics another main concern is if wearable haptic device are socially acceptable or not as the feeling of touch can be perceived in different ways. In the coming sections different types of wearable haptic devices are mentioned with examples of already existing devices, but most of them are just prototypes currently. Also the pros and cons of the haptic device are briefly mentioned.
3 2. Haptic scarf The haptic prototype called TapTap (see Figure 2) is a wearable haptic device that allows asynchronous distributed transmission of tactile information to be recorded, broadcast and played back for emotional therapy. This haptic scarf is envisioned as a comfortable personalized garment that a child could use or a therapist for the patient to provide some element of nurture and affection. Figure 2. TapTap, the wearable haptic scarf Haptic input/output modules in a convenient modular scarf provide affectionate touch that can be personalized and replayed. The haptic prototype scarf has pockets into which actuators or a wallet and keys can be placed (see Figure 3). Different actuators is placed in different pockets, and the system works only when the scarf is held against the body. Figure 3. Inserting the flexible input/output haptic device into the scarf
4 The linear arrangement and the vibrating motors are arranged concentrically and activate from the centre out and back to simulate pressing. Two solenoid configurations are used: a large single solenoid that acts to expand and contract inside a cloth pocket, and a circular array of small solenoids at an oblique angle meant to feel like fingers tapping. Recording is achieved through momentary switches attached to large plastic contact pads. [Bonanni et al., 1997] 2.1. Challenges with haptic scarf The haptic scarf is a very interesting device and can promote the affectionate touch that could help people to feel better. But of course as any other haptic device even this device has its own challenges. This prototype relies on an external power source for driving the solenoids and heat pumps. A proper wearable version would be limited to the low-power vibrating coin motors as actuators. Also more sophisticated sensing will be necessary to record touch more precisely [Bonanni et al., 1997]. User studies on social, emotional impact and acceptance needs to be done and apart from that, also the design of the scarf needs to be improved so that is can be more comfortable to wear.
5 3. Haptic Hug shirt The device called "Hug from a Distance" (see Figure 4) is a vest that can be electronically controlled to give someone a hug over the Internet. It copies the strength, length, temperature and heart rate of the hug. Using WiFi or Bluetooth technology and their cell phone, the hug can be sent to someone else wearing a Hug Shirt that simulates the feeling of the hug. After four seconds of pressure, an electronic valve opens and releases the air. The device then sends an acknowledgement saying the hug was received, and thanks the sender with a kissing sound. Figure 4. The hug from a distance shirt This remote hug could be rejected or reciprocated by the remote receiver. When reciprocated, the jackets would remain synchronized in hug mode until either of the parties chose to end the hug. It supports stroking and patting in a physical way. It is flirtatious, playful and it involves a high degree of reciprocity. Also, it permits couples to express private and discrete signs of affection in public places. [Vetere et al., 2005] This device was mainly designed and intended for sharing intimate affection between lovers who are geographically apart. But apart from that, children with autism spectrum disorders who calm with pressure might also benefit from this type of vest. The limitation of this haptic hug from a distance shirt is that it does not explain why or how expressions of intimacy occur, nor is it comprehensive. Also studies on social or cultural impact on such haptic device need to be recorded, as it could be perceived as sexual.
6 4. Haptic massage therapy Humans seek home like comfort wherever they go and also while travelling. People find it stressful when they have to travel a lot and also feel tired due to the journey. Body massaging help people to relax and also to feel better, also massage is done as treatment for body pains too. The haptic prototype called Touch Sensitive is a haptic apparel that allows massage therapy to be diffused, customized and controlled by people while on the move. It provides individuals with a sensory cocoon, a comforting and alerting apparel with a feedback system (see Figure 4). Made of modular garments, this prototype applies personalized stimuli. Figure 4. Vinyl pockets filled in with liquid that diffuses around the massaging wooden ball through thermoelectric sensors. It is a matrix made of clothing elements that allow diffusion of haptic information through heat sensors, mechanically driven textural sensation and liquid diffusion. The user could even choose between hot and cold using the same thermoelectric sensors. This prototype allows the diffusion of haptic information through computational and mechanical technologies. It is a computerized touch therapy apparel whose modular pieces can be integrated within the clothing. A feedback embedded microphone/headphone in the clothing also allows the user to control the system. It is manually actuated and takes advantage of the body morphology to trigger the desired actuation. [Cati Vaucelle and Yasmine Abbas, 2007] The problem with this design is that since it diffuses massage oil or liquid and also the user could even choose between hot and cold it needs to be worn inside the clothes so as the clothes doesn t mess up. But since it is intended to use in pubic this device is not practical as it is not common to undress in pubic for a massage therapy. The design needs to be improved so that it could be used in pubic without having to remove any sort of clothing.
7 5. Haptic garments 5.1. Haptic sports garment Haptic sports garment (see Figure 5), which use tactile signals to prompt the user to optimise their technique or to use specific muscle groups, were tested on rowers. Figure 5. Haptic sports garment. Sensors in the garments measure the speed at which the rower moves and how they coordinate their leg and body movements. If the rower deviates from the optimum speed or rhythm, pads worn at the ankle and waist start vibrating at the correct stroke intervals. Thus help the rower recapture the optimum speed or rhythm. [Hendrik and Jan van, 2003] According to Hendrik-Jan van Veen of the Netherlands Organisation for Applied Scientific Research in Soesterberg; the feedback can be understood by the person much more quickly than if they are getting instructions from a human trainer.
8 5.2. Haptic Suit for Improved Human Motor Learning The haptic suit is designed to help teach people physical activities. It analyses the movements of the behaviour and provides instant feedback to the user. To learn some movements, the student receives real-time tactile feedback, simultaneously over all joints, delivered through this wearable haptic suit (see Figure 6). This tactile feedback can supplement the visual or auditory feedback from the teacher. The results from the experiments conducted by the researches at the Massachusetts Institute of Technology, using this suit showed a 27% improvement in accuracy while performing the target motion, and an accelerated learning rate of up to 23%. [Lieberman and Breazeal, 2007] Figure 6. Haptic suit. This haptic suit is intended for use in various activities including sports training, motor rehabilitation after neurological damage, dance, postural retraining for health, and many more. But the challenge with this device is that it could become annoying or uncomfortable after a while of using it and might become difficult in following the tactile feedback.
9 6. Haptic gloves Haptic gloves are part of the equipment that is being used in the development of a wide range of virtual reality devices. In fact, the haptic glove is a mechanism that is shaped like the human hand allowing for the insertion of the human hand and the easy movement of the fingers. However, haptic gloves also contain electronic wiring and devices that help to stimulate sensation and allow for an interface with electronic images. The function of haptic gloves is usually built around two main applications. In one type of interactive activity, the gloves allow the user to receive stimulation along the fingertips that mimics actual physical contact with an object or another person. The sensations are connected to an electronic simulation, such as in a video game. Haptic technology allows the individual wearing the gloves to not only view the virtual simulation, but also to physically interact with it. Along with allowing for the creation of an artificial sense of touch, haptic gloves also allow the user to move the fingers and impact the movement within the virtual simulation. Thus, the user is able to use the gloves to help the virtual self move around in the virtual reality and interact with the other elements of the reality. The sense of movement and touch will seem perfectly natural to the person wearing the gloves, and can be very entertaining. A wide range of applications for the use of haptic gloves in the development of virtual reality devices is currently taking place. The potential applications include medical simulations that can be used in training a new generation of healthcare professionals, the development of a number of next generation video games, and even in the production of personal adult entertainment devices. [Malcolm Tatum, 2008]
10 6.1. Haptic glove that enable user to feel panels and switches It is a very demanding task when evaluating complex design (such as cockpits) based on visual sense. Some researchers at Tampere University of Technology developed tactile feedback devices, such as a haptic glove, which enable user to feel panels and switches. This wearable haptic glove, which is based on McKibben actuators, enables user s unlimited movement in virtual environment. [HandsOn, 2008] Figure 6. Haptic glove which enable user to feel panels and switches 6.2. Musical haptic gloves The musical haptic gloves allow their users to create musical compositions by linking hands together. Each participant wears the gloves, headphones (through which they can hear their personal music) and a clip-on box housing circuits. When they touch the gloved hand of another, they can hear their own music mixed with the other person's sound. The more people holding hands, the more sophisticated the track gets. Figure 7. Musical haptic gloves The interaction through physical touch attempts to physically bring people together even if they don't speak the same language. [Kaho Abe and Jung Sin 2005]
11 7. Summary Wearable haptic devices have come a long way with many interesting innovative ideas and prototypes to help bring the sensation of touch feel more real and practical to use. Wearable haptics devices not only help people to feel better mentally and physically but also could help users to learn or improve their skills or even get creative or just feel relaxed and also help relieve body pain or stress. Designing and developing a wearable haptic device could be a challenge and it needs lots of studies and research too. Apart from the technology, the user requirements need to be understood when designing a wearable haptic. Most of the current designs need a lot of improvements to make it feel and look more natural, comfortable to wear and also easy to carry or travel with, but currently that is not the case with many of the prototypes mentioned in this paper. The current functionality of the devices is not yet up to the level that it could be used conveniently in public. Lot more studies and research needs to be done to improve the haptic technology and designing wearable haptics.
12 References [Answers.com, 2008] Haptic. Available: http://www.answers.com/haptic [Harlow, 1950-1960] Harry Harlow. Touch research in primates. Available: http://www.hkjpaed.org/johnson/touchinlabourandinfancy/02.htm [Bonanni et al., 1997] Leonardo Bonanni, Jeff Lieberman, Cati Vaucelle and Orit Zuckerman. TapTap: A Haptic Wearable for Asynchronous Distributed Touch Therapy. Available: http://web.media.mit.edu/~amerigo/taptap.pdf (checked on 05 October 2008) [Van Veen and van Erp, 2003] Hendrik A.H.C van Veen and Jan B.F. van Erp. Haptic sports garments. Available: http://www.we-make-money-notart.com/archives/2005/09/as-if-being-baw.php [Hendrik and Jan van, 2003] Hendrik A.H.C van Veen and Jan B.F. van Erp. Providing Directional Information with Tactile Torso Displays. Available: http://www.eurohaptics.vision.ee.ethz.ch/2003/71.pdf [Lieberman and Breazeal, 2007] Jeff Lieberman and Cynthia Breazeal. Development of a Wearable Vibrotactile Feedback Suit for Improved Human Motor Learning. Available: http://robotic.media.mit.edu/pdfs/journals/liebermanbreazeal-tro- 07.pdf [Vaucelle and Abbas, 2007]. Cati Vaucelle and Yasmine Abbas. Touch Sensitive Apparel. Available: http://pubs.media.mit.edu/pubs/papers/touchsensitive.pdf [Kaho Abe and Jung Sin 2005] Haptic Glove. Available: http://a.parsons.edu/~kaho/hapticglove/. [HandsOn 2008] Multimodal Interaction in Engineering Design. Available: http://www.tml.tkk.fi/research/handson/tty.html [Malcolm Tatum, 2008] What are Haptic Gloves? Available: http://www.wisegeek.com/what-are-haptic-gloves.htm [Vetere et al., 2005] Frank Vetere, Martin R. Gibbs, Jesper Kjeldskov, Steve Howard, Florian Floyd Mueller, Sonja Pedell, Karen Mecoles, Marcus Bunyan. Mediating Intimacy: Designing Technologies to Support Strong-Tie Relationships. Available: http://floydmueller.com/achievements/intimacy.pdf