Hairware: The conscious use of unconscious auto-contact behaviors

Katia Vega Pontifical Catholic University of

Rio de Janeiro Rua Marquês de São Vicente, 225 - Gávea, Rio de Janeiro -

RJ, Brazil kvega@inf.puc-rio.br

Marcio Cunha Pontifical Catholic University of

Rio de Janeiro Rua Marquês de São Vicente 225 – Gávea, Rio de Janeiro –

RJ, Brazil mcunha@inf.puc-rio.br

Hugo Fuks Pontifical Catholic University of

Rio de Janeiro Rua Marquês de São Vicente, 225 - Gávea, Rio de Janeiro -

RJ, 22451-900, Brazil hugo@inf.puc-rio.br

ABSTRACT Beauty Technology is a wearable computing paradigm that uses the body’s surface as an interactive platform by integrating technology into beauty products applied directly to one’s skin, fingernails and hair. Hairware is a Beauty Technology Prototype that connects chemically metalized hair extensions to a microcontroller turning it into an input device for triggering different objects. Hairware acts as a capacitive touch sensor that detects touch variations on hair and uses machine learning algorithms in order to recognize user’s intention. Normally, while someone touches her own hair, unconsciously she is bringing comfort to herself and at the same time is emitting a non-verbal message decodable by an observer. However, when she replays that touch on Hairware, she is not just emitting a message to an observer, because touching her hair would trigger an object, creating in this way, a concealed interface to different devices. Therefore, Hairware brings the opportunity to make conscious use of an unconscious auto-contact behavior. We present Hairware’s hardware and software implementation.

Author Keywords Hairware; Conductive Hair; Beauty Technology; Wearable Computers; gesture recognition.

ACM Classification Keywords H.5.2 Information interfaces and presentation: User Interfaces; Haptic I/O.

INTRODUCTION Given today’s wearables revolution, the human body will become a new design standpoint. Thus, the next logical step in wearable computers seems to be the use of the body’s roughly two square meters of skin as a canvas for applying sensors and attaching other computing devices in ways that enhance human experience. The body surface, i.e., the skin, nails and hair, plays crucial roles as a protective barrier, sensory monitor, heat and moisture regulator, and an integral part of the body’s immune system. Nevertheless, humanity, since its inception, has used beauty products to adorn the body for a variety of reasons. Nowadays, beauty products have become quite sophisticated with advances in chemistry but have remained mostly aesthetically oriented. Even though the $382 billion global beauty business market is mostly supported by women and 4 in 5 women wear makeup [10], beauty products still have not been thoroughly explored in relation to their possible use as wearable computers. Beauty Technology [23,24,25] disrupts this frontier by placing technology directly on the body surface and allowing women to use beauty products to control their environment through technology in a personal, seamless and fashionable way.

When embedding technology into everyday life objects, Weiser envisioned it functioning in an invisible and unobtrusively way [27]. For that reason, minimizing awareness while interacting with technology, continue to be an important guideline in Ubiquitous Computing. Our concern with this vision is that users are not consciously aware that these pieces of technology are gathering data and processing it for them. In contrast, we propose interactions that the user is consciously aware of and intends to generate them, though in a concealed way, by enacting auto-contact behaviors. Thus, the invisibility of the interaction is not hidden to the user but it is hidden to the observer.

It is worth to remember that there are two interactions taking place. One with the observer as a result of the auto-contact behavior and another, concealed from the observer, with the object. According to the literature [12], auto-

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contact behavior is to bring comfort to oneself: Does the concealed interaction increase one’s own comfort?

The hair is public as everyone could see it, personal as it is a body part, and malleable as it suits cultural and personal preferences [7]. It has for centuries been a vital decorative organ but also it is a powerful source of communication, often being employed as an additional gender signal that differentiates males than females, and as a badge of age and status [12]. In addition to the way it looks, the way it is touched expresses a whole set of non-verbal messages. A woman with longish hair that throws the hair backward attempts to make herself more visible to the opposite sex, but this can also be done in a rather aggressive manner, such as during an argument for making her looks a little larger to her opponent [6]. Straightening the hair over and over again like when a woman tucks her hair behind her ear continuously, is often a sign that indicates anxiety [6]. Twirling the hair around a finger is a gesture that mimics the innocence of childhood and is often used as a flirtation device and as something that a person does when she's bored or trying to settle herself down [6]. Those self-intimacies are movements that provide comfort because they are unconsciously mimed acts of being touched [12]. Conversely, this work aims to recognize conscious touches on hair using those conventional self-intimacies. The wearer touches her Hairware and only she would know what device is being triggered.

This work proposes the use of Hairware as a novel electronic device to be used in wearable computing. We used a chemical platting technique that makes the artificial hair extensions to be conductive but, at the same time, remains looking like regular human hair. This paper introduces Hairware, a capacitive touch sensor that detects a variety of touches for the triggering of different devices. Section 2 identifies previous work on body technologies as input devices. Section 3 presents the hardware and software implementation to detect touch on Hairware. Section 4 shows the model used for learning and recognizing touches on hair. Section 5 presents the evaluation results and

reviews the lessons learned using Hairware. Conclusion and future work are shown in the last section.

RELATED WORK Wearable Computing changed the way individuals interact with computers, intertwining natural capabilities of the human body with processing apparatus [27]. Most of this technology has been designed just for clothing or accessories. However, some works place technology on the body’s surface. Thus, the skin and its regenerative appendages (i.e. hair and nails) not just play the crucial role in human beings but also embedded electronics to act as input devices. For example, Skinput [8] uses a bioacoustics microphone to sense the vibration that occurs when the body is tapped. Another example is Senskin [15], a wearable device that uses multiple IR reflective sensors implanted in an armband to allow the skin to be used as a soft input interface by comparing the actual force and the sensor values using an elastic model of the human skin. Touché [18] is a sensing technology that proposes a Swept Frequency Capacitive Sensing technique by using bracelets that detects touches on different parts of the body by sensing the impedance variability between electrodes. Thus, the user could put the phone into silent mode by making a “shh” gesture bringing her index finger to the lips.

In previous Beauty Technology prototypes, Conductive Makeup [23,24,25] was presented as an interface for detecting voluntary blinking. Conductive Makeup includes conductive eyeliner and chemically metalized fake eyelashes that act as blinking switches. While conductive eyeliners (Figure 1a) connect sensors and actuators by using conductive materials that stick to the skin, replacing conventional eyeliners, conductive fake eyelashes (Figure 1b) sense blinking. In order to prove the feasibility of the prototype as a conductive component, some applications were developed. Blinklifier [25] uses blinking for switching LEDs on and off on an artistic headdress. Arcana [23] uses blinking for changing music tracks and images visualizations. Superhero [24] is another artistic application that makes use of Conductive Makeup for triggering a remote control to levitate an object (Figure 1c).

Figure 1. Beauty Technology: Conductive Makeup [23]. (a) Conductive eyeliner that connects the eyelashes to the circuit; (b)

Chemically metalized fake eyelashes; (c) Application that makes use of Conductive Makeup for flying a drone by blinking.

a) b) c)

Figure 2: Interaction through wearables (a) Google Glass [5]; (b) Talk to the hand [14]; (c) Sixthsense [11] .

Wigs could be used as to enhance someone’s appearance and also to follow cultural and religious traditions. SmartWig [22] is a wearable device that uses a wig for hiding electronics that communicates wirelessly with other external devices. SmartWig suggests applications that could fulfill a number of functions, from acting as a health care device that monitors users’ vital signs to helping blind people navigate roads, or changes slides in a presentation by tapping their sideburns, under which buttons are hidden. A further potential improvement of the wig may use ultrasound waves to detect objects around a user. Hair accessories that vary from clips to corsages, designed to give every look a final flourish, could also be used for creating discreet and fashionable gadgets attached to the hair. First Sign Hair Clip [20] is an electronic hair clip that communicates with a mobile application to automatically call for help and collect evidence when the user is in danger. By using accelerometers and gyroscopes, it detects head impacts associated with violent crimes, automatically triggering an alarm, while evidence is collected by a microphone.

CONCEALED INTERACTION Weiser [27] envisioned a ubiquitous computing paradigm where technology is integrated into everyday experiences in a way that computers vanish into background. In this way, the major challenge of the Disappearing Computer paradigm [21] is the development of new invisible technologies that fit the task so well that the tool becomes a part of the task [13]. This approach converges in the use of implicit interactions where the user concentrates on her prime goal or targeted activity—tool use is intended, but the user isn’t actually aware of the interaction with the computer system. In contrast, we propose using explicit interactions meaning that a user operates a system aiming to achieve a certain goal—that is, the user is fully aware of the tool that she is using.

Mainstream research focuses more in creating technologies that users get so used to them that the task becomes invisible rather than investing on the invisibility of the device. Currently, the human body is becoming an important topic in the field of human-computer interaction due to the proximity of wearables to the body combined with the aim of processing user’s data in everyday objects.

However, there is no doubt that current wearable technologies are nevertheless very distinguishable. On the other hand, recently there have been some efforts in making technology disappear, as is the case with Ringly [16], a jewelry device that connects to smartphones and gives the user notifications. Ralph Lauren’s Polo Tech shirt [9] is another example of seamless fashionable technology that contains conductive silver threads and sensors designed to measure user’s performance looking like a classic sport shirt. Moreover, instead of using clothing and accessories, Beauty Technology [23] uses beauty products to hide technology and place them straight on the body surface.

Interactions through gestures and body movements are clearly visible to any user’s observers. Figure 2 shows some examples of wearable’s interactions through gestures that by touching them in a certain way (Google Glass [5] in Figure 2a), simulates a known gesture (Talk to the Hand Project [14] in Figure 2b) and also creates new gestures (Sixthsense Project [11] in Figure 2c). There has being previous exploration using clothes and accessories such as PocketTouch detects finger-strokes through fabric [17], CheekyWear that mimics a flirting gesture for triggering actions [2] and Cord Input that detects grasping, pulled and twisted gestures on a cord [19]. In contrast, we are proposing an interface that uses the own body surface where the non-verbal communication is not straightforwardly decoded. Non-verbal communication modalities might include body motion or kinesics behavior such as facial expression and posture; paralanguage such as laughing and yawning; proxemics; olfaction; skin sensitivity; and the use of objects such as a dress and cosmetics [3]. In this way, most wearable gadgets use body motion for sensing gestures. Body motions comprise four types of cues that convey information about the nature and the intensity of an emotion: body acts (clear movements), body positions (non movement of a body part), facial expressions, and head orientations. [4]. In this research, we used auto-contact behaviors [12], a body act that takes place whenever we touch, stroke or hug ourselves in order to provide comfort and sometimes suggests anxiety or sexual invitation. For example, this kind of act could also be classified as an adaptor [3] that is triggered by an unconscious feeling that the person rarely intends to

a) b) c)

communicate and the observer is typically not aware of. In this way, we conceal the interaction with the wearable device, creating a concealed interface (Figure 4). For example, in a social meeting, a Hairware user touches the tip of Hairware to make her phone rings, touches the middle to put her phone in mute mode and touch the top to send a pre-customized message to a colleague. In this way, she will continue her activity at the meeting and, at the same time, not straightforwardly noticed, she will be interacting with her phone.

IMPLEMENTATION APPROACH Our implementation comprises the hardware and software development of the prototype. The hardware connects the conductive hair extensions to a circuit. While touching, the software detects on it and identifies the user’s intention.

Hardware Hairware is artificial hair extensions that were chemically metalized for acquiring electrical conductivity and also keeping a natural coloration. The chemical process is carried out in two phases: Activation and Electrolysis. During the first phase, artificial hair extensions, being plastic non-conducting surfaces, require some kind of activation to enable them to be submitted to an electrochemical process. For the first activation, hydrogen and tin (II) chloride are used (Figure 3a). Then, a silver nitrate solution is added for the second activation, where the extensions are set up to catalyze electron transfer reactions, making them ready for metalizing. Next, electrolysis is used for platting them. Copper is electrochemically deposited for making them electrically conductive (Figure 3b and 3c) while “black nickel” gives the natural black effect (Fugure 3d). We used a Hairware strand of approximate 1.5 by 25cm and with a surface resistivity of less than 5 ohm/sq. We could dismiss the step of black nickel electrolysis but we added it for getting dark hair coloration. However other reagent could be used instead of it for getting a different color.

Hairware is connected to a circuit to work as a capacitor sensor. This circuit creates a delay in the pulse that is the time the capacitor takes to charge and discharge. In this way, Hairware is used as a conductive surface that detects

when another conductive surface approximates to it. Therefore, as the human body is conductive, the average internal resistance of a human trunk is ~100 Ω [26], touching Hairware will affect capacitance and result in a different charging time.

We use hair clips for attaching the circuit to the hair extensions in order to be easily removable and replaceable. Also this makes it possible to put the circuit in different accessory such as a hairclip, headband, brooch and the top of the hair extensions.

Figure 3 - Hair Extensions during the chemical process: (a)

After activation 2, (b) copper electrolysis, (c) Copper Acid, (d) Black nickel electrolysis.

Figure 4: Concealed Interaction through Hairware.

Auto-contact Behavior

Non-verbal message User’s intention

a) b)

c) d)

Figure 5 shows 3 layers of non- conductive hair extensions that are added for isolating the hair from the skin. Also, these layers improved the capacitor sensor values. Each time the user touch the top, middle or tip, the capacitor sensor differentiates these values. The circuit compares an output that transmits the pulse and an input, which receives the pulse. When a finger touches Hairware, it creates a delay in the pulse, and this delay is recalculated by the Arduino microcontroller. The circuit diagram (Figure 6) is also composed with four 1MΩ resistors and one 100pF capacitor. The resistors selects the sensitivity, bigger the resistor, the farther away it detects a human. With 4MΩ resistor between the output and input pins the circuit is tuned to start to respond one inch away, just the sufficient to overcome the non-conductive hair layer. The small capacitor (100 pF) placed from sensor pin to ground improves stability and repeatability. Some LEDs were added to the system to give feedback to the user whenever a touch is detected (Figure 7).

Figure 5 – Changing the capacitance of Hairware by non-conductive artificial hair extensions

Figure 6- Hairware Circuit using Arduino

Figure 7 –Visual feedback while touching the hair

Software For classification, we use a decision tree implementation provided by BigML [1]. Each transmission from the sensor contains a capacitive charging time in milliseconds, from which we extract for classification. Currently, we can classify five touches interaction in the Hairware: no touch, touch on the top, touch on the middle, touch on tip and straightening.

When trained, the decision tree build an actionable model (Figure 8) that we use as an Arduino function to classify the interaction in real time. Each node represents the confidence action from the read value. The key feature to recognize touch on the hair is not to detect the touch itself, but the circuit must be fined tune to detect small capacitance charge variation along the hair.

Figure 9 shows data collected from the five interactions used to classification evaluation. The charts plotted from this data set show the charging time difference from each interaction. As expected the touch on the tip has the higher value due to that layer of non-conductive hair is thinner (layer 3). The charging value will decrease when the interaction gets near the top where there are more non-conductive hair layers acting as a filter. The straightening actions have the lowest values due to its speed and skin contact time with the sensor. The “No Touch” graph ranges from zero to 60 because the hair gets in contact with the human skin without configuring a touch, (no other touch got these low results.) “Touch in Top” moves to 1000, “Middle” to 1500, “Tip” to 2200 and “Straightening” to 750. That is because the Hairware layers’ design sets apart touch from the conductive material, by making the top of the hair having a lower capacitance (because it is more covered) and the tip of the hair more expose (the capacitance is higher.) Noise appeared on the readings given that the hair was in direct contact with the skin. However, our algorithm recognizes it as noise and obtains 92% accuracy on the five trained touch gestures.

Non–conductive hair extensions

Layer 1

Layer 2

Layer 3

Conductive Hair

EVALUATION For our evaluation, we aim to identify the exposure of the technology in Hairware and also we measure the accuracy in replaying the hair straightening, top, middle, and tip touch. We recruited 5 female participants, ranging in age from 28 to 35. We made our evaluation with female participants because most of them use or had used long hair, they are more knowledgeable about hair care and its looks and they are the ones who do auto-contact behaviors with their hair. The study took approximately 30 minutes per each participant and included a gratuity. Given that Hairware is a proof of concept of the technology, evaluations were taken in the same laboratory under the same conditions (temperature, humidity and pressure). We acknowledge that geotemporal factors will affect the results and a calibration method is required. At the beginning, we conducted pre-questionnaires to identify the participants’ profiles. All participants were right handed. They do not own any wearable technologies but everyday they use other electronic devices like smartphones and tablets. None used before a hair extension but they knew what was it and they

saw them applied in other person. All of them expressed that they touch their hair when they feel anxious, thoughtful and nervous. Three of them noticed them using their hair as a flirting tool.

Figure 8 - Confidence from the decision tree

Figure 9: Capacitor Sensor Values in the different touches (a) No Touch; (b) Touch on the Top; (c) Touch on the Middle; (d) Touch on the Tip; (e) Straightening

Figure 10 – Participant testing different touch on Hairware

We interview the participants before they observe and use the wearable device. We asked them questions related to Hairware visibility and their use of hair extensions. While showing Hairware, we asked them about their impressions about it, if they could identify a difference between this hair extensions, and normal or artificial hair. Then we showed a non-conductive artificial hair extension and asked about the differences they could detect between them and Hairware.

After 2 minutes of training on the different tasks, we asked them to reply the different 5 touches. They made each touch 10 times. Figure 10 shows the participant touching the top, middle and bottom part of Hairware during the test. Finally an interview asking for recommendations and future uses was conducted.

RESULTS AND DISCUSSION After listening the answers of the first interview, we identified that, at first sight, Hairware wasn’t noticed as a technological device and they weren’t aware of its conductivity. Most of the participants thought it was natural hair extensions and when compared it with the artificial hair, they noticed that the artificial hair extension is more shining and with a smoother texture. They also expressed that, when Hairware would be attached to someone’s hair, the difference between it and natural hair wouldn’t be noticeable.

During the tests, we observed that, even that each touch was perceptible by our algorithm, a previous calibration must be done for each user. Differences in skin capacitance and hand position whenever are doing the touches could make the capacitor sensor identify different values for each user. We also notice that other feedback must be designed. LEDs won’t be notice if the user is wearing Hairware. We will replace this feedback by vibration motors.

After using Hairware, they expressed that it was easy to use and adding the layers of non-conductive artificial hair extensions, gave the device a shinny look and it was smooth to touch. They expressed that, if the circuit is hidden into the hair or into a accessory, an external observer wouldn’t notice the device. Future versions of Hairware will also add

the touches that the participants exposed that they usually perform: twirling their hair and passing the fingers through the head.

During the final interview, participants expressed that they would use Hairware for specific purposes. Most of them recommended using it as a security device. That is, when they feel in danger or are located in a risky area, they would like to send a message to the police or to someone they trust without anyone around noticing that she is doing it. Another suggestion was to use it as an input device for triggering house appliances. Thus, they could turn on and off from anywhere. Another suggestion was to use it as an alarm each time she is making continuously her nervous tick. Also, it would be used as a therapy for relaxing when the device noticed she is stressed.

Our approach is to use Hairware as an input device that senses human touch on hair that are not noticeable by an external observer. In this way, depending on the way Hairware is used, there are some concerns related to privacy that could be controversial. For example, a Hairware user could start recording a conversation without authorization of the observer.

Due to the skin resistance, Hairware must be placed on any non-conductive material for isolating it from the skin like a shirt. Also other conductive materials like jewelry could affect the way it operates. Our design covers it with layers of non-conductive hair extensions. Future works will include a new step in our chemical process that isolates all conductive hair extensions but preserving its capacitance sensitivity.

CONCLUSION AND FUTURE WORK The main contribution of this work is the design of novel interfaces that are hidden, i.e. no one knows that the user is wearing such device; that make it possible concealed interactions, i.e. no one knows that the user is triggering an event; and that the body surface is being used as a novel wearable interface by transforming materials into devices that look like body parts. Thus, we add new functionalities to hair extensions, turning them into a seamless device that recognizes auto-contact behaviors concealed to outside observers. Hairware was designed using artificial hair extensions that are chemically metalized to maintain a natural coloration and when connected to a microcontroller could be used as an input device. Thus, not just the technology is seamless but also the action of touching her hair that trigger devices are hardly noticed by an external observer. Touching her hair is an unconscious action that woman do for getting more comfort. This action rarely intends to communicate and the observer is typically not aware of, making it less noticeable than other gestures like winking or waving hands. Using Hairware, they will replay this act on her hair but she is not just emitting a message to an observer, she would be triggering an object, creating a concealed interface to different devices. In this way,

Hairware brings the opportunity to make conscious use of an unconscious auto-contact behavior.

This paper explained our processes in designing the interface, creating the hardware and implementing the algorithm for detecting a touch on the top, middle, tip, straightening the hair and no touch. A study case was conducted with 5 participants to identify if the technology is noticeable by an observer and for testing our gesture recognition system. We used 80% of the data of each different touch to train our model and 20% for testing its accuracy. Then, again, we tested the model with the users to verify whether the touches were being interpreted correctly. The prototype achieved 92% accuracy on five touch gestures. The prototype was tested in the laboratory under the same conditions. Non-intended gestures and other factors could affect the results and a calibration method would be required. Future works will include an activation gesture such as pressing Hairware for a few seconds.

We used Hairware as an input device that consciously used unconscious auto-contact behaviors to trigger different devices such as a TV, Home appliances and Smartphones. We envision the use of Hairware in situations whenever the interaction is intended to be hidden such as in certain meetings, fir secret agents and for magicians. However, Hairware could explore the different meanings of hair in terms of culture and emotions. A new study case that senses the unconscious auto-contact behaviors in order to understand the levels of stress and anxiety when the user touches her hair could be conducted. Also, as hair is generally a focus of women, Hairware could be used as a tool for protection against risky situations. In this way, it could be used as an alarm device that send messages with the user’s location but also it could embed an RFID and other sensors in order to provide more evidence to the law court and the police.

Future works will include the use of Hairware not just as hair extensions but also as other hair replacements as beard. Other sensors, such as accelerometers and gyroscopes will be integrated on the hair extensions to make combinations of movements and hair touch.

ACKNOWLEDGMENTS Marcio Cunha (grant 163066/2013-2) and Hugo Fuks (Project 302230/2008-4) are recipients of grants awarded by the National Research Council (CNPq). This work was partially financed by Research Support Foundation of the State of Rio de Janeiro-FAPERJ/INCT (E-26/170028/2008) and CNPq/INCT (557.128/2009-9). Katia Vega is a postdoctoral fellow with grant funding from PNPD/CAPES Portaria 086/2013.

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