Marcin Kempiński

Three-dimensional (3D) printing techniques already enable the precise deposition of many materials, becoming a promising approach for materials engineering, mechanical engineering, or biomedical engineering. Recent advances in 3D printing enable scientists and engineers to create models with precisely controlled and complex microarchitecture, shapes, and surface finishes, including multi-material printing. The incorporation of artificial intelligence (AI) at various stages of 3D printing has made it possible to reconstruct objects from images (including, for example, medical images), select and optimize materials and the printing process, and monitor the lifecycle of products. New emerging opportunities are provided by the ability of machine learning (ML) to analyze complex data sets and learn from previous (historical) experience and predictions to dynamically optimize and individuate products and processes. This includes the synergistic capabilities of 3D printing and ML for the development of personalized products.

The article addresses the development of an innovative mechanical and information technology (IT) solution in the form of a three-dimensional (3D) printed hand exoskeleton, enabling the rehabilitation of people with special needs (with the participation of physiotherapists). The design challenges and their solutions are presented in the example of the own design of a prototype mechanical rehabilitation robot (a hand exoskeleton) to support the rehabilitation process of people with a lack of mobility in the hand area (both as a result of disease and injury). The aim of this paper is to develop the author’s concept for a hand exoskeleton developed within an interdisciplinary team during the design work to date. The problem solved in the study was to develop a five-finger 3D-printed hand exoskeleton providing physiological ranges of movement and finger strength support at a level at least half that of healthy fingers, as well as taking it to the clinical trial phase. The novelty is not only an interdisciplinary approach but also focuses on developing not only prototypes but a solution ready for implementation in the market and clinical practice. The contribution includes the strong scientific and technical, social, and economic impact of the exoskeleton on the hand due to the fact that any deficit in hand function is strongly felt by the patient, and any effective way to improve it is expected in the market. The concept of the hand exoskeleton presented in the article combines a number of design and simulation approaches, experimentally verified mechanical solutions (a proposed artificial muscle, 3D printing techniques and materials, and possibly other types of effectors supported by sensors), and IT (new control algorithms), along with the verification of assumptions with a group of medical specialists, including in laboratory and clinical settings. The proposed specification of the hand exoskeleton offers personalised dimensions (adapted to the dimensions of the user’s hand, as well as the type and level of hand function deficit), weight (approximately 100–150 g, depending on the dimensions), personalised actuators (described above), all degrees of freedom of the healthy hand (in the absence of defects), and the time to close and open the hand of approximately 3–5 s, depending on the level and degree of deficit.