PROJECT SUMMARY Although static neck braces are prescribed to patients with head drop resulted from amyotrophic lateral sclerosis (ALS), many patients do not use these neck braces because they are uncomfortable and ineffective. As a result, patients leave their head drop condition untreated, which worsens their ability to breathe, swallow, speak, and perform other daily tasks. The long-term goal is to treat ALS head drop through an at-home assistive device. The overall objective in this application is to build a structurally suitable neck exoskeleton for ALS head drop, with comfortable and easy-to-wear attachments, as well as robust mechanical linkages and joints. The central hypothesis is that a structurally suitable neck exoskeleton will improve overall users’ satisfaction, increase head-neck range of motion, and enable social interactions. The rationale for this project is that once a structurally suitable neck exoskeleton becomes available, it will likely offer a feasible platform to support future clinical trials and facilitate its translation for domestic use. The central hypothesis will be tested by pursuing one specific aim: Determine mechanical factors of a suitable neck exoskeleton critical for ALS head drop. Under this aim, patients with ALS head drop will be involved in the design process and precisely made components will be used to build a structurally suitable neck exoskeleton. It will then be evaluated by patients with severe ALS head drop to determine the extent to which this neck exoskeleton increases head-neck range of motion, enables social interaction, enhances head-neck movement precision, and achieves overall satisfaction of these participants. The research proposed in this application is innovative, in the applicant’s opinion, because it focuses on achieving a structurally suitable neck exoskeleton to empower head-neck movements in patients with ALS head drop by incorporating patients’ feedback and utilizing advanced design and manufacturing methods. The proposed research is significant because it is the next fundamental step in the continuum of research that is expected to provide clinically available neck exoskeleton specifically targeted for ALS.