ABSTRACT Recent research on in‐plane switching liquid crystal displays (IPS‐LCDs) employing ferroelectric nematic (NF) LC, 3FM‐C4T, revealed a fast‐response impulse‐type modulation of transmission efficiency (TE) under the application of rectangular‐wave voltages at 130°C in the NF phase. This study demonstrates that impulse‐type TE modulation is a universally observed phenomenon in LCs with significant polarization. The results indicate that the impulse‐type TE modulations are not limited to 3FM‐C4T, but can also be realized in other LC systems. Notably, impulse‐type TE modulations are demonstrated in the N phase for both DIO and RM734. Furthermore, based on the generalized understanding that NFLCs exhibit impulse‐type TE modulation in both the NF and N phases, a blended LC composed of conventional NLC and NFLC is fabricated, and it exhibits the impulse‐type TE modulation at approximately room temperature with a reduced driving voltage. Additionally, to elucidate the observed phenomena, nematic relaxor ferroelectrics are proposed to play a contributory role. These findings contribute to the expansion of NFLC research and broaden the range of applications and potential for practical implementation of impulse‐type TE modulation.

In skill acquisition, learners’ motivation plays an important role. Based on embodied cognition and haptic learning, we hypothesized that vibro-acoustic stimuli could serve as valuable feedback to enhance motivation. In this study, three experiments explored whether such stimuli strengthen learners’ task-specific confidence in their cooking abilities. Experiment 1 examined the discriminability of vibro-acoustic stimuli as feedback. Sounds and vibrations were recorded when a professional chef and an amateur cut two types of food, and were presented via a haptic device to participants, who evaluated the sensations. Participants successfully distinguished between the two performers solely through the vibro-acoustic stimuli. Experiments 2 and 3 investigated how vibro-acoustic stimuli corresponding to food cutting affect task-specific confidence. Participants who actively experienced the stimuli while watching a professional chef’s video showed greater confidence than those who only felt the stimuli passively. These findings point to the potential applicability of vibro-acoustic stimuli in facilitating certain aspects of cooking skill acquisition, although the current work is an exploratory step toward integrating haptic cues into cooking education rather than a demonstration of performance improvement.

The orientation and electro-optical properties of in-plane switching liquid crystal displays (IPS LCDs) filled with a newly developed ferroelectric nematic liquid crystal (NFLC), 3FM-C4T, are investigated. The 3FM-C4T-based IPS LCDs exhibit a uniform, homogeneous orientation and robust orientation stability, equivalent to those of nematic LCs. In addition, unlike conventional nematic LCDs, a fast-response impulse-type transmission efficiency (TE) modulation occurs in LCDs with 3FM-C4Ts, in which the TE changes only for a moment when the polarity of the applied voltage reverses. The novel impulse-type TE modulation is identified for the first time and differs from the impulse-type emission observed in self-luminous displays in the sense that the TE increases and decreases during an ON signal. This phenomenon occurs because the polarization vector of the 3FM-C4Ts, which are oriented symmetrically with no voltage, becomes asymmetric under the application of an electric field below the coercive electric field, resulting in shielding voltage for the 3FM-C4T layer via the polarization of the thin polyimide alignment layer and a corresponding decrease in the effective applied voltage to the 3FM-4CTs. The proposed LC device effectively improves the image quality of LCDs and is useful for many other applications requiring fast-response impulse-type TE and polarization modulation.

Prolonged hospitalization of newborns (e.g., extremely preterm infants or extremely low birth weight infants) in Neonatal Intensive Care Units (NICUs) often limits physical interactions between parents and their infants, potentially impairing parental mental health and parent-child bonding. Research has shown that skin-to-skin contact reduces postpartum depression and enhances parental sensitivity. However, in-person visitation is often restricted by factors such as time and geographical barriers. This study introduces an online system for embodied communication, where families hold a haptic feedback device with a display against their chest as if holding an infant. The device allows families to view live video of their infant while feeling their infant's heartbeat through vibrotactile feedback. The system was evaluated against two types of online visitation: screen-based visuals only and screen-based visuals with vibrotactile feedback. The proposed system improved parents' psychological closeness to their infant, giving a sense of holding their infant and offering comfort. These findings emphasize the value of multisensory interfaces in family-centered neonatal care.

When designing a haptic interface, simplicity is crucial to avoid negative effects caused by excessive weight and complexity. Using multimodal information, haptic illusions, and providing context are known to create simpler interfaces. We have previously proposed the use of single overlapped vibrotactile stimulation (SOVS) for presenting spatiotemporal tactile perception, a method that simultaneously presents overlapped waveforms to multiple body parts. There, the acceleration measured from a person dribbling a basketball with an accelerometer positioned on the index finger and the floor was overlapped to present as stimuli. When the stimuli were presented simultaneously to the hand and the feet, it demonstrated a dribbling sensation, like an imaginary ball moving back and forth between the hand and the feet. This demonstrated the potential to eliminate the need for time synchronization and reduce the number of required channels, ultimately leading to the development of simple haptic interfaces that enhance an immersive experience. In this paper, we aim to investigate the key factor behind the perception of SOVS using simple vibrotactile stimuli. The first experiment measured the occurrence rate of the dribbling feeling for different combinations of prepared stimuli, and the results show that the combination of two different input amplitudes is crucial for the occurrence rate of the phenomenon. The second experiment assessed how realistic each stimulus, presented to the hand and the feet separately, felt to the participants. The results show that for the hand, the perceived reality corresponded to the strength of input amplitude, whereas the second-strongest input amplitude was perceived as most realistic for the feet. This suggests that when the combination consists of duplicate input amplitudes and/or those with low perceived reality, the occurrence rate tends to decrease.

The effects of tactile information sharing on empathy and reward systems in interpersonal interaction are significant. Recent technological developments have enabled tactile information sharing in remote communication, but its effects on brain plasticity have not been investigated. To this aim, using functional magnetic resonance imaging (rs-fMRI), we investigated whether conveying tactile information during remote communication induces plastic changes in functional connectivity. Seventy participants participated in conversations either with or without tactile stimulation. During the social interaction phase, participants engaged in a 15-minute conversation with the experimenter. Afterward, the tactile group showed a higher emotional connection score than the control group. Notable plastic changes in functional connectivity were observed in the striatum-orbitofrontal cortex and striatum-inferior frontal gyrus of the tactile group compared to the control group. In addition, a significant correlation between emotional connection and the connectivity between the anterior cingulate cortex and supramarginal gyrus was identified. These findings suggest that remote tactile communication systems have the potential to amplify emotional experiences and foster enhanced interpersonal connections in virtual interactions.

Experience Sampling Method (ESM) is a research procedure for monitoring ever-changing subjective emotions in our daily lives. A typical method asks participants, several times a day, to report and rate their emotions in terms of pre-defined adjective scales (e.g., “2 for sad,” and “5 for happy”). When a scale includes many adjectives, rating time is increased for participants. However, when few adjectives are provided, respondents may struggle to find descriptors that truly match their internal state, making it difficult to express the complex nuances of multiple emotions. This paper reports the development of a novel approach to ESM in which participants choose only a single word that intuitively expresses common emotion categories and intensities with minimal demands on their time. To achieve this capability, we conducted a survey with 14,321 Japanese speakers that presented a list of intuitive and embodied emotional expressions such as mimetics(e.g., “thump-thump”) and interjections (e.g., “wow”) in Japanese, categorized according to the eight primary emotions and three levels of emotional intensity used in the Plutchik model, and asked them to choose the expressions they use in their daily lives. The results showed that the most frequently used expressions were generally consistent irrespective of gender or age, and that people differentiated their use of expressions according to the category and intensity of their emotions. Our findings indicate that it is possible to create a single common list of expressions that can be used by all genders and ages to efficiently and intuitively express nuanced emotions appropriate to their inner states without the person having to think deliberately.

Haptic information is useful in various fields, and presenting stimulation to multiple points en-riches the experience. Independent Vibrotactile Stimulation to multiple points (IVS) evokes a tactile apparent motion. We propose Single Overlapped Vibrotactile Stimulation (SOVS) with imagination to produce spatiotemporal perception like IVS. The SOVS combines the stimulation of IVS. We developed a pseudo-dribbling system that produces a feeling of an imaginary ball moving between the hand and the feet where the same stimulation was given. To examine the feeling by SOVS, the first experiment on changing the speed of the stimulation showed the SOVS can produce a similar feeling to the IVS, indicating SOVS allows participants to match the perceived stimulation to the stimulation according to the dribbling being imagined. The second experiment was conducted using an obstacle between the hand and the feet to interrupt the image. We controlled the interruption by controlling attention. Results showed that both IVS and SOVS overcome the obstacle to evoke a piercing feeling under the attention to the floor, whereas IVS still provided a piercing feeling under the attention to the obstacle but SOVS could not provide it, suggesting the possibility that the perception mechanism is different between the SOVS and IVS.

Although electrostatic actuators have a simple structure and are lightweight, their range of application is limited because a high applied voltage of more than several kilovolts is required for practical use. Since the force acting between the electrodes of an electrostatic actuator is determined by the electric charge accumulated at the electrode/dielectric interface, the focus is on spontaneous polarization of ferroelectrics to increase the charge. As the ferroelectric material, a nematic liquid crystal material with a spontaneous polarization of 5 mu C cm-2 is used. It is demonstrated that a force of 1.3 N is generated at an applied electric field of 0.5 MV m-1. This force is 1200 times higher than that for standard paraelectric materials with a dielectric constant of ten. Further, the generated force responds linearly to the applied voltage, whereas it is proportional to the square of the applied voltage for paraelectric materials. The actuator function of this ferroelectric is examined using a double-helical coil electrode fabricated using a 3D printer. It can be successfully operated at a voltage of several tens of volts. Under an electric field of 0.25 MV m-1, a remarkable contraction of 6.3 mm occurs, corresponding to 19% of the original length. A ferroelectric nematic liquid crystal material with a spontaneous polarization of 5 mu C cm-2 is applied to an electrostatic actuator rapid-prototyped using a 3D printer and resin plating. With this material, the generated force responds almost linearly to the applied voltage and is 1200 times greater than that for conventional paraelectric materials. image

This study developed a tactile transmission system with a wearable squeezing display that works under an existing online communication system. Half of 32 participants used the wearable tactile display and the other did not use it. Psychological state and behavioral measures were conducted at the pre and post communication. The results showed the state change with tactile stimulus, and the possibility of behavior change was discussed.

The high five is a widely used communication gesture that promotes cooperation and trust between people. This paper presents a remote communication system that enables people to experience the feeling of high fiving remotely. Each remote location is equipped with a video monitor along with a transparent surface placed in front. When one user high fives the tactile surface, the corresponding surface of the other user vibrates to convey the sensation. We verified the feasibility of the proposed system for delivering an emotional experience among the athletes and their family members by installing this system at a sports event.

The quality of the dietary habits of older adults is important for increasing healthy life expectancy. As with other physical senses, the senses of taste and olfaction change with age. In contrast to physical sensations that can be visibly compared with those of other people, taste and olfaction are personal sensations, making it challenging to infer associated changes. This study investigated the characteristics of taste and olfaction in healthy older adults and compared them with those of young adults. In the taste assessment, threshold values were measured using the whole-mouth method with a diagnostic assay kit (Tastedisc). The olfactory assessment measured the overall identification ability using a card-type olfactory identification test kit (Open Essence). Additionally, participants’ subjective health awareness was measured using a visual analog scale. The taste and olfactory assessments results showed that the older group had lower overall sensory sensitivity than the young group, and that there was no correlation between taste and olfactory sensitivity in the older group, while a trend was observed in the young group. Moreover, there was no significant difference between the two groups regarding subjective health awareness, indicating that participants in our research considered themselves healthy regardless of age. This suggests that the subjective health awareness of older people in the health promotion class is somehow independent from their sensory ability.

By integrating haptic presentation technology and certain haptic sensors into online real-time communication, we can acquire subjective information on others through the sense of touch, and use it as a new standard for our own behavior. We believe that this will lead to changes in people's altruistic behavior, including cooperative behavior. This study investigates behavioral changes during tactile sharing using a behavioral economics scheme. We adopted a sequential public goods game where several participants in a group must exchange money. The haptic condition, where the investment points that other player put can be recognized with vibrotactile sense, and the visual condition, where the investment points that other player put can be visually recognized, were prepared. 32 participants were divided into the visual-first and haptic-first groups, and the haptic or visual condition was alternated between the 1st and 2nd sessions. The results showed significant effects on the haptic experience and correlations with guilty, indicating that the tactile sharing amplified feelings of guilt and made people less likely to act uncooperatively.

The goal of this study was to demonstrate the influence of prior auditory and visual information on speech perception, using a priming paradigm to investigate the shift in the perceptual boundary of geminate consonants. Although previous research has shown visual information such as photographs influences the perception of spoken words, the effects of auditory and visual (written or illustrated) information have not been directly compared. In the present study, native Japanese speakers judged whether or not a spoken word was a geminate word after hearing/seeing a prime word/pseudoword that contained either singleton or geminate feature. The results indicate the spoken words, written words and even illustrations presented prior to the target sounds, can guide boundary shift for Japanese geminate perception. Significantly, the influence of auditory information is independent of the lexical status of the primes, that is, both word and pseudoword auditory primes with geminate sound features induced a significant bias. On the other hand, visual primes induced the bias only when the primes coincided lexically with the targets, indicating the influence of visual information on geminate perception is different from auditory information.