In the last decade, we have witnessed a drastic change in the form factor of audio and vision technologies, from heavy and grounded machines to lightweight devices that naturally fit our bodies. However, only recently, haptic systems have started to be designed with wearability in mind. The wearability of haptic systems enables novel forms of communication, cooperation, and integration between humans and machines. Wearable haptic interfaces are capable of communicating with the human wearers during their interaction with the environment they share, in a natural and yet private way. This paper presents a taxonomy and review of wearable haptic systems for the fingertip and the hand, focusing on those systems directly addressing wearability challenges. The paper also discusses the main technological and design challenges for the development of wearable haptic interfaces, and it reports on the future perspectives of the field. Finally, the paper includes two tables summarizing the characteristics and features of the most representative wearable haptic systems for the fingertip and the hand.

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Wearable Haptic Systems for the Fingertip and the Hand: Taxonomy, Review, and Perspectives

The development of dynamic hand orthoses is a fast-growing field of research and has resulted in many different devices. A large and diverse solution space is formed by the various mechatronic components which are used in these devices. They are the result of making complex design choices within the constraints imposed by the application, the environment and the patient’s individual needs. Several review studies exist that cover the details of specific disciplines which play a part in the developmental cycle. However, a general collection of all endeavors around the world and a structured overview of the solution space which integrates these disciplines is missing. In this study, a total of 165 individual dynamic hand orthoses were collected and their mechatronic components were categorized into a framework with a signal, energy and mechanical domain. Its hierarchical structure allows it to reach out towards the different disciplines while connecting them with common properties. Additionally, available arguments behind design choices were collected and related to the trends in the solution space. As a result, a comprehensive overview of the used mechatronic components in dynamic hand orthoses is presented.

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A structured overview of trends and technologies used in dynamic hand orthoses.

https://ro.uow.edu.au/cgi/viewcontent.cgi?article=1204&context=eispapers1

Disturbance observer based Takagi-Sugeno fuzzy control for an active seat suspension

Active control of an innovative seat suspension system with acceleration measurement based friction estimation

This paper presents the design, fabrication and testing of an innovative active seat suspension system for heavy-duty vehicles. Rather than using conventional linear actuators, such as hydraulic cy...

https://journals.sagepub.com/doi/pdf/10.1177/0263092316676389

An active seat suspension design for vibration control of heavy-duty vehicles

https://purehost.bath.ac.uk/ws/files/114545262/JSV_Paper_Revised_6_3_15.pdf

Adaptive control of an active seat for occupant vibration reduction

Stroke is very common and always leads to severe hand impairment. Traditional robotic systems have been introduced to assist therapy for a long time and already achieved certain effect. However, with further development of therapy strategies in the last few years, higher request to the rehabilitation robot has been put forward. Thus, we are developing a novel hand rehabilitation robot named HIT-glove to provide patient-cooperative therapy for hand-impaired post-stroke patients. In this paper, the mechanical design of the actuated hand exoskeleton is detailed and the control strategy for patient-cooperative therapy is introduced. The actuated hand exoskeleton, which can be applied to hands in different sizes and shapes, is able to bilaterally actuate every joint of the fingers. The patient-cooperative control strategy, based on the sensing system and an interactive interface, is well designed to let the patient actively participate into the therapy. Besides, to get a better effect of functional rehabilitation of the hand, our robot is expected to provide the following two categories of therapy: motor function exercise for joints and movement coordination training for fingers.

Design and development of a hand rehabilitation robot for patient-cooperative therapy following stroke

In this article, the biodynamic responses of seated human subjects (SHS) exposed to whole-body vibration (WBV) in both vertical and fore-and-aft directions are modelled. The mathematical model can be used to obtain a better insight into the mechanisms and biodynamic behaviour of the SHS system. The main limitation of some previous SHS models is that they were derived to satisfy a single biodynamic response function. Such an approach may provide a reasonable fit with the function data being considered but uncertain matches with the others. The model presented in this study is based on all three types of biodynamic response functions: seat-to-head transmissibility (STHT), driving-point mechanical impedance (DPMI) and apparent mass (APM). The objective of this work is to match all three functions and to represent the biodynamic behaviour of SHS in a more comprehensive way. Three sets of synthesized experimental data from published literature are selected as the target values for each of the three transfer functions. A curve fitting method is used in the parameter identification process which involves the solution of a multivariable optimization function comprising the root mean square errors between the computed values using the model and those target values measured experimentally. Finally, a numerical simulation of the frequency response of the model in terms of all three biodynamic functions has been carried out. The results show that an improved fit is achieved comparing with the existing models.

Biodynamic modelling of seated human subjects exposed to uncouples vertical and fore-and-aft whole-body vibration

Even though numerous organic dyes which are used as photoinitiators/photocatalysts during photopolymerization have been systematically investigated and collected in previous reviews, further designs of these chromophores and the developments in high-performance photoinitiating systems have emerged in recent years, which play the crucial role in 3D printing/Vat polymerization. Here, in this mini-review, various families of organic dyes that are used as newly synthesized photoinitiators/photocatalysts which were reported in literature during 2021–2022 are specified by their photoinitiation mechanisms, which dominate their performance during photopolymerization, especially in 3D printing. Markedly, visible light-induced polymerization could be employed in circumstances not only upon the irradiation of artificial light sources, e.g., in LEDs, but also in sunlight irradiation. Furthermore, a short overview of the achievements of newly developed mechanisms, e.g., RAFT, photoinitiator-RAFT, and aqueous RAFT using organic chromophores as light-harvesting compounds to induce photopolymerization upon visible light irradiation are also thoroughly discussed. Finally, the reports on the semiconducting nanomaterials that have been used as photoinitiators/photocatalysts during photopolymerization are also introduced as perspectives that are able to expand the scope of 3D printing and materials science due to their various advantages such as high extinction coefficients, broad absorption spectra, and having multiple molecular binding points.

/pdf/3d-printing-vat-photopolymerization-of-photopolymers-f1lb6zxn.pdf

Zengkang Gan

Papers

Adaptive control of an active seat for occupant vibration reduction

Design and development of a hand rehabilitation robot for patient-cooperative therapy following stroke

Biodynamic modelling of seated human subjects exposed to uncouples vertical and fore-and-aft whole-body vibration

Biodynamic modelling of seated human subjects exposed to uncouples vertical and fore-and-aft whole-body vibration

3D Printing/Vat Photopolymerization of Photopolymers Activated by Novel Organic Dyes as Photoinitiators