Biological monitoring technology based on pressure sensing is a very useful for human diagnosis method as an assistive equipment, which should be comfortable on wearing position for user as well as and patient. Especially, pressure monitoring for prosthetic arm and artificial leg is the critical element to maintain the safety of the amputees. In this research, the fabrication and characterization of a novel flexible pressure sensor was done to measure the actual working pressure between the surface of human body and assistive device for biomechanical techniques. The ultimate goal of the sensor design is targeted for use in robotic and prosthetic limb, where feedback and ability to detect forces associated with slip is crucial point. To fabricate the capacitive type pressure sensor, finite element method (FEM), additive manufacturing (3D-printing) and signal processing were used. FEM simulation was performed with Comsol S/W for optimal structure design to evaluate with the structural deformation and maximum capacitance value up to 500 kPa in sensor range. Sensor with a full scale volume thickness under 10 mm were produced using FDM 3D-printingtechnique. A passive two-terminal electrical component part of capacitive pressure sensor was fabricated with conductive thermoplastic material and medium side of dielectric layer to keep soft and flexible structure. The output signal from the pressure sensor and related signal processing system was connected to a voltage divider circuit to amplifying the signal, multiplexer, microcontroller unit included analog to digital converter and indicating program. As a result, capacitive pressure sensing technology embedded in 3D printed structure can be considered for maintenance of stability and comfortability to amputees.
ZnO nanowires (NWs) would provide significant enhancement in sensitivity due to high surface to volume ratio. We
investigated the first methodical study on the quantitative relationship between the process parameters of solution
concentration ratio, structure, and physical and properties of ZnO NWs grown on different flexible fabric surfaces. To
develop a fundamental following concerning various substrates, we controlled the growth speed of ZnO NWs and
nanowires on cotton surface with easy and moderate cost fabrication method. Using ammonium hydroxide as the
reactant with zinc nitrate hexahydrate, ZnO NWs layer have been grown on metal layers, instead of seed layer. ZnO
NWs fabrication was done on different fabric substrates such as wool, nylon and polypropylene (PP). After the ZnO
NWs grown to each substrates, we coated insulating layer with polyurethane (PU) and ethyl cellulose for prevent
external intervention. Detailed electrical characterization was subsequently performed to reveal the working
characteristics of the hybrid fabric. For electrical verification of fabricated ZnO NWs, we implemented measurement
impact test and material properties with FFT analyzer and LCR meter.
To monitor hypertrophic scars in burnt skin we proposed and demonstrated a hybrid polymer/carbon tube-based flexible pressure sensor. To monitor the pressure on skin by measurement, we were focusing on the fabrication of a well-defined hybrid polydimethylsiloxsane/functionalized multi-walled carbon tube array formed on the patterned interdigital transducer in a controllable way for the application of flexible pressure sensing devices. As a result, the detection at the pressure of 20 mmHg is achieved, which is a suggested optimal value of resistance for sensing pressure. It should be noted that the achieved value of resistance at the pressure of 20 mmHg is highly desirable for the further development of sensitive flexible pressure sensors. In addition we demonstrate a feasibility of a wearable pressure sensor which can be in real-time detection of local pressure by wireless communication module. Keywords: