Study and development of stretchable sensors for flexible surgical instrumentation.

Recently, attention has been focused to minimize the invasiveness of existing minimally invasive surgery (MIS) approaches: one example is the development of continuum-like and soft robots that can bend, extend, contract at any point along their length. This provides them with capabilities well beyond those of their rigid-link counterparts, thus allowing to perform whole arm manipulation. One recent approach to soft and modular systems is represented by the on-going EU project STIFF-FLOP (www.stiff-flop.eu). The STIFF-FLOP arm is not fabricated by rigid structures, but soft ones showing advanced manipulation capabilities for surgical applications, with multiple degrees of freedom (DOFs), and ability of multi-bending. Ideally, the entire robotic structure should safely move with contact and bend detection and the embedded sensors should not interfere with the movements: the use of small sensors, both soft and stretchable, which remain functional when deformed, becomes necessary. For the aforementioned reasons, we introduce a small, low-cost, soft and stretchable sensor composed of a silicone rubber (EcoFlex0030, SmoothOn), integrating a conductive liquid channel filled with biocompatible Sodium Chloride (NaCl) solution. By stretching the sensor the cross-section of the channel deforms, thus leading to a change in electrical resistance. The functionality of the sensor has been proved through testing: changes in electrical resistance are measured as a function of the applied strain. The advantage of using silicone rubber is its mechanical durability and high flexibility, non-toxicity, chemical stability and low cost. Furthermore, liquid conductors eliminate the need for rigid electronics and preserve the natural elasticity of the sensor, and the NaCl solution fulfills the need for a biocompatible liquid. Differently from existing solutions that are not truly stretchable and biocompatible, the contribution of this work is an effort for improving the current soft sensors technologies through the demonstration that NaCl filled channel rubbers represent a valid solution for measuring deformations in flexible surgical instrumentation

Soft Active Materials for Actuation, Sensing, and Electronics

Future generations of robots, electronics, and assistive medical devices will include systems that are soft and elastically deformable, allowing them to adapt their morphology in unstructured environments. This will require soft active materials for actuation, circuitry, and sensing of deformation and contact pressure. The emerging field of soft robotics utilizes these soft active materials to mimic the inherent compliance of natural soft-bodied systems. As the elasticity of robot components increases, the challenges for functionality revert to basic questions of fabrication, materials, and design - whereas such aspects are far more developed for traditional rigid-bodied systems. This thesis will highlight preliminary materials and designs that address the need for soft actuators and sensors, as well as emerging fabrication techniques for manufacturing stretchable circuits and devices based on liquid-embedded elastomers.Engineering and Applied Science

Stretchable interconnects for smart integration of sensors in wearable and robotic applications

Stretchable electronic systems are needed in realising a wide range of applications, such as wearable healthcare monitoring where stretching movements are present. Current electronics and sensors are rigid and non-stretchable. However, after integrating with stretchable interconnects, the overall system is able to withstand a certain degree of bending, stretching and twisting. The presence of stretchable interconnects bridges rigid sensors to stretchable sensing networks. In this thesis, stretchable interconnects focusing on the conductive polymer Poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate) (PEDOT:PSS) , the composite and the metallic-polyimide (PI) are presented. Three type of stretchable interconnects were developed including gold (Au) -PEDOT:PSS hybrid film interconnects, Graphite-PEDOT:PSS composite interconnects and Au-PI dual-layered interconnects. The Au-PEDOT:PSS hybrid interconnects’ stretchability can reach 72%. The composite exhibits a stretchability of 80% but with an extremely high variation in resistance (100000%). The Au-PI interconnects that have a serpentine shape with the arc degree of 260° reveal the highest stretchability, up to 101%, and its resistance variation remains within 0.2%. Further, the encapsulation effect, cyclic stretching, and contact pad’s influence, are also investigated. To demonstrate the application of developed stretchable interconnects, this thesis also presents the optimised interconnects integrated with the electrochemical pH sensor and CNT-based strain sensor. The integrated stretchable system with electrochemical pH sensor is able to wirelessly monitor the sweat pH. The whole system can withstand up to 53% strain and more than 500 cycles at 30% strain. For the CNT-based strain sensor, the sensor is integrated on the pneumatically actuated soft robotic finger to monitor the bending radius (23 mm) of the finger. In this way, the movement of the soft robotic finger can be controlled. These two examples of sensor’s integration with stretchable interconnects successfully demonstrate the concept of stretchable sensing network. Further work will focus on realising a higher density sensing and higher multifunctional sensing stretchable system seamlessly integrated with cloth fibres

Design of an e-textile sleeve for tracking knee rehabilitation for older adults

The occurrence of total knee replacements is increasing in the United States for persons over the age of 45 because they are inexpensive and a very effective method for treating degenerative joint diseases. Rehabilitation requires regular access to a wide variety of resources and personnel and, as the demand for post-operative, rehabilitative care increases, the ability to marginally relieve the healthcare system by offloading resources to the patient is necessary. Tools to enable tracking a patient’s rehabilitative progress at home are an essential method to help unload the healthcare system. The purpose of this project is to design and develop a wearable home rehabilitation device for knee replacement. This thesis utilizes design ethnography tools such as expert interviews, rehabilitation observation, a participatory design workshop, iterative development, and an idea feedback study. Leveraging advancements in technology and the field of eTextiles, this study investigates the product feasibility and acceptance of discreet on-body sensors to provide a product that enables patients to better perform rehabilitation on their own, but also to allow for a feedback loop for physicians and therapists to view patient progress.M.S

Um estudo para o desenvolvimento de peças de vestuário com sensores têxteis incorporados com a função de prevenir má postura corporal

O objetivo geral deste estudo é reunir conhecimento e informações necessárias para desenvolver ou utilizar sensores têxteis, para que futuramente esses, possam ser integrados a peças do vestuário. Essas peças serão dirigidas para pessoas que necessitem ter consciência da própria postura corporal. A meta é que essas peças possam ser utilizadas no quotidiano das pessoas, com a função de prevenir má postura corporal, fornecendo feedback direto para os usuários. A utilização deste vestuário poderá auxiliar na conscientização da postura, auxiliando as pessoas a terem um melhor posicionamento corporal em seu dia a dia. Esta dissertação decorre no mesmo fluxo do processo de design. Inicia-se com a teoria, em um aspeto amplo e generalizado, passando a tópicos mais específicos e então culminando em um protótipo. A primeira parte serve de embasamento para que a segunda seja produzida. Trata-se de uma pesquisa exploratória de novas funcionalidades para o design de moda. Embasada pelo contexto da moda tecnológica e do design interativo, desembocando no design de moda como resposta a problemas. Analisando a coluna vertebral e a má postura corporal, esta pesquisa procura compreender se os sensores têxteis podem ser o melhor dispositivo a ser empregado para a prevenção deste problema. Uma peça de roupa é então apresentada para exemplificar, de forma física, o trabalho desenvolvido por essa dissertação. A conclusão do trabalho é que os sensores têxteis são o material ideal a ser empregado no desenvolvimento de peças de vestuário com a função de prevenir a má postura corporal.This study aim´s on gathering knowledge and information needed, in order to develop or use textile sensors. The idea is that in the future, those can be integrated into clothing. These clothes will be built to people who need to be aware of their own body posture. The goal is that those clothes can be used in everyday life, with the function of preventing bad back posture, providing direct feedback to users. The use of this clothing may assist in the awareness of posture, helping people to have a better body position on a daily basis. This dissertation follows the same process flow of the design. It begins with the theory, in a broad and general aspect, becoming more specific and then culminating in a prototype. The first part serves as background in order for the second part be produced. This is an exploratory research of new features for fashion design. Grounded by the context of fashion technology and interactive design, arriving into fashion design as a response to problems. Analyzing the spine and bad posture, this research seeks to understand whether the textile sensors may be the best device to be used to prevent this problem. A garment is then presented to exemplify, in physically, the work of this dissertation. The conclusion of the work is that the textile sensors are the ideal material to be used in the development of garments with the function of preventing poor posture

再装填機構を備えた能動緩衝外装を持つ等身大ヒューマノイドの実現に関する研究

学位の種別:課程博士University of Tokyo(東京大学