This project explores the potential of a material system based on SMAs that generates haptic feedback for Visually Impaired People (VIPs). Since VIPs rely more than others on tactile information, there is a need for more natural and unintrusive haptic devices as the commonly used electromechanical actuations are often perceived as intrusive and less acceptable than non-vibrating feedback. SMAs emerge as a promising solution to address these challenges effectively, due to their inherent ability to create silent, organic sensations, while being lightweight, thin, and flexible (Cruz et al., 2018).

The aim of this project is to investigate the unique characteristics of SMAs and translate this into an integrated material system that could inspire designers to adopt these materials and revolutionize tactile experiences. The process had an explorative nature and included a research, form configuration and embodiment phase. Most current haptic systems based on SMAs have the limitation of small actuation ranges and/or difficulties in integrating them in soft material systems. Therefore, in this project, a soft integrated material system is designed that shows the potential of incorporating SMA and SE flat springs into an origami-paper textile to create haptic feedback.
By using the combination of the SMA-SE flat springs, an easy integration of the wires in the paper-textile is enabled and a two-way actuation is created with a displacement of around 16%. Through the use of the origami structure, the two-dimensional shape change of the SMA spring is transformed in a three-dimensional shape change creating rich tactile feedback that can be perceived passively as well as actively.

The sensations generated by the material system were easily perceived with the hands and the movement was characterized as natural, calm and gentle by sighted participants. This demonstrates that there is a potential for creating an integrated material system based on flat springs SMAs that generated haptic feedback for VIPs in a natural and new way. Additionally, based on all these findings, a guideline was developed for SMA wires with the aim to give an overview of all steps involved when designing a material system based on SMAs.

Anxiety is a natural “fight-or-flight” response that everybody experiences to perceived stress or threat. Even though it is a natural response, some individuals struggle with managing their anxiety levels in a healthy manner. Prolonged exposure to high anxiety states can lead to clinical anxiety disorders that negatively impact the quality of life, thus early interventions to reduce anxiety levels can help prevent the development of clinical level anxiety. Even nonclinical individuals can also suffer from periods of heightened anxiety state, so anyone can benefit from additional guidance with anxiety modulation.

This graduation project aims to create a wearable garment that helps with daily levels of anxiety modulation in a non-clinical setting by providing warmth and pressure sensations typically associated with Deep Touch Pressure (DTP). DTP is a form of tactile sensory input that is provided by holding, stroking, hugging and squeezing, which has been proven to elicit feelings of safety, relaxation, and comfort. Although there are some commercially available DTP wearable products typically in the form of a vest, they are often heavy, uncomfortable, or indiscreet as the DTP sensations are provided by additional weights or inflatables with hand-operated pumps. Since they are difficult to conceal, wearing those commercial DTP vests can attract unwanted attention from nearby strangers and further aggravate anxiousness. Instead, DTP sensations can be applied to the body in a noiseless, lightweight, and discreet manner by utilizing shape memory alloy (SMA) actuators in wearable garments.

The insights that formed the groundwork for this project was gathered through literature review in a wide variety of topics including haptic technology, affect regulation, and SMA. Deeper understanding of the intricate nuances involved with anxiety modulation were gained through self-reflection and introspection as part of the autobiographical design method. Although the insights gathered from introspection are rooted in subjective lived experiences, they can yield universally applicable outcomes based on genuine empathy and firsthand understanding that resonate with a broader range of users who experience similar or related difficulties with anxiety. Moreover, rapid prototyping and iterative processes were utilized to tinker with and learn about designing SMA based actuators for wearable garments. After fabricating several prototype iterations, each exploring different design variables, SereniSleeve was developed.

SereniSleeve is a fingerless glove sleeve that provides warmth and deep pressure sensations to the forearm. It helps users break out of spiraling anxious thoughts by providing on-body haptic sensations that they can focus on, enhancing their grounding techniques. User test participants experienced feelings of calmness, relaxation, and comfort at varying pressure settings. Users can intuitively activate the sleeve by clenching their fists during stressful or anxious situations, triggering one of three preset pressure settings depending on the user applied force. All the electronic components can easily be detached from the double-layered fabric sleeve cover for easy maintenance and washability. Based on the participant feedback, future work and iterations on SereniSleeve could further improve its overall usability and user experience.