Brewster, StephenAlotaibi, Yosuef2023-06-092023-06-092023-06-05https://hdl.handle.net/20.500.14154/68304Electrotactile feedback is a novel haptic feedback modality that can be used to evoke a desired level of alertness and emotion or convey multidimensional information to the user. However, there is a lack of research investigating its basic design parameters and how they can be used to create effective tactile cues. This thesis investigates the effect of Electrotactile feedback on the subjective perception of specific sensations, such as urgency, annoyance, valence and arousal, to find the number of distinguishable levels in each sensation. These levels are then used for designing structured, abstract, electrotactile messages called Electrotactons. These have potential benefits over vibration-based cues due to the greater flexibility of the actuators. Experiments 1, 2 & 4 investigated the effects of manipulating the basic electrotactile parameters pulse width, amplitude and pulse frequency on perceived sensations. The results showed that all parameters have a significant effect on the perceived sensations, except for pulse frequency not having an effect on valence. Also, pulse frequencies of 30 PPS and above did not influence the perceived sensations. Experiment 3 investigated the use of pulse width, amplitude and pulse frequency to convey three types of information simultaneously encoded into an electrotactile cue. This was the first attempt to design Electrotactons using the basic parameters of electrotactile feedback. The results showed overall recognition rates of 38.19% for the complete Electro- tactons. For the individual component parameters, pulse width had a recognition rate of 71.67%, amplitude 70.27%, and pulse frequency 66.36%. Experiment 5 investigated intensity and pulse frequency to determine how many distinguishable levels could be perceived. Results showed that both intensity and pulse frequency significantly affected perception, with four distinguishable levels of intensity and two of pulse frequency. Experiment 6 investigated the use of intensity and pulse frequency from in Experiment 5 to improve the design of Electrotactons on three body locations using two different size electrodes. The results showed overall recognition rates of up to 65.31% for the complete Electrotactons. For the individual component parameters, intensity had a recognition rate of 68.68%, and pulse frequency 94.41%. These results add significant new knowledge about the parameter space of electrotactile cue design and help designers select suitable properties to use when creating electrotactile cues.184enHCIHuman-Computer InteractionHapticsSubjective perceptionElectrotactile FeedbackElectrotactonsThesis