Proposition of Design and Rationale for a Therapeutic Stimulation Tool for ASD Adolescents with SPD

Autism spectrum disorder is a neurodevelopmental condition that often co-occurs with sensory processing differences. Individuals with those conditions often display sensory-seeking behaviors and sensory understimulation that lead to distress or unintended self-harm. While existing fidget devices are popular, it is suggested that their emphasis on visual or tactile stimuli proves to be ineffective at sensory-grounding in autistic individuals. This paper proposes the design of a cost-effective, low-tech therapeutic stimulation tool specifically for adolescents (17-18 years old) with ASD and SPD. The design aims to channel sensory craving behaviours through controlled, targeted proprioceptive and tactile stimuli – offering a safe and more accessible mimic to sensory integration therapy. The tool is designed as a bistable hand-gripper; it requires an optimised grip force of approximately 7.5 kg, encouraging repetitive muscle contraction that alleviates sensory underload. In order to ensure safety and durability for low-functioning autistic individuals – specifically against blunt force or mouthing – the tool includes a fatigue-resistant, polyether-based thermoplastic polyurethane core surrounded by high-density memory foam for deep pressure stimulation. The exterior uses a food-grade, textured silicone cladding and impact-resistant polypropylene blocks, deliberately avoiding fragile mechanisms, electronic components, or toxic materials. The next steps of the research would focus on prototyping and testing to evaluate the device's feasibility in minimising sensory understimulation within the target population in daily life.