Effect of Microneedle-Assisted Auricular Vagus Nerve Stimulation on Attention.

Transcutaneous auricular vagus nerve stimulation (taVNS) is an established non-invasive technique to modulate neural activity and enhance cognitive functions. Traditional adhesive electrodes used in taVNS, however, often lack precision, resulting in inconsistent stimulation and undesirable side effects. To address these challenges, this study proposes a novel microneedle-based approach, which holds potential applications extending to traditional Chinese acupuncture. This experimental study, conducted with 180 healthy adult participants, investigates the effects of microneedle-assisted taVNS on motivation and effort through pupillometry. Participants underwent taVNS using both microneedles and adhesive electrodes. Key physiological metrics-pupil size, heart rate, and blood oxygen levels-alongside cognitive metrics such as reaction time and error rates in a computer game, are assessed. Results reveal that microneedle-assisted taVNS significantly enhanced all measured parameters, attributed to its precise and consistent stimulation of the auricular branch of the vagus nerve. This study highlights the superiority of microneedle-based taVNS over traditional adhesive electrodes in terms of stimulation accuracy, cognitive performance, and physiological regulation. Additionally, it explores the potential application of microneedles in acupuncture, offering a safer, more precise, and controlled alternative to conventional needles.