A high-density amperometric electrode array containing 8192 individually addressable platinum working electrodes with an integrated potentiostat fabricated using Complementary Metal Oxide Semiconductor (CMOS) processes is reported. The array was designed to enable electrochemical imaging of chemical gradients with high spatiotemporal resolution. Electrodes are arranged over a 2 mm × 2 mm surface area into 64 subarrays consisting of 128 individual Pt working electrodes as well as Pt pseudo-reference and auxiliary electrodes. Amperometric measurements of norepinephrine in tissue culture media were used to demonstrate the ability of the array to measure concentration gradients in complex media. Poly(dimethylsiloxane) microfluidics were incorporated to control the chemical concentrations in time and space, and the electrochemical response at each electrode was monitored to generate electrochemical heat maps, demonstrating the array's imaging capabilities. A temporal resolution of 10 ms can be achieved by simultaneously monitoring a single subarray of 128 electrodes. The entire 2 mm × 2 mm area can be electrochemically imaged in 64 seconds by cycling through all subarrays at a rate of 1 Hz per subarray. Monitoring diffusional transport of norepinephrine is used to demonstrate the spatiotemporal resolution capabilities of the system.
Hand rehabilitation is one of the most important rehabilitation procedures. Due to the repetitive nature of rehabilitation training, a full robotic system could help the physiotherapists to gain time for creating new training schemes for a larger number of patients. Such a system can be based on live or recorded data and consists of the operatordevice, patient-device, and control mechanism. This paper focuses on the design of the patient-device and its control-system in a decoupled training scenario. It presents a robot for hand rehabilitation training fingers and wrist independently based on only two actuators. These two actuators are configurable to allow consecutive training on the wrist and all joints of the fingers. To overcome uncertainties and disturbances, a sliding mode controller has been designed and an adaptive fuzzy sliding mode controller is used to reduce the chattering effects and compensate the varying forces of the patients. The experimental results show an approximate 80% improvement in tracking the desired trajectory by the adaptation.
More efficient cooling systems are an enabler for the increase in power-density in an electric traction motor. Contemplating to existing reviews, this paper presents a comprehensive collection of heat transfer mechanisms for the different heat removal techniques used in electric traction motors. In the first section, an overview of various cooling concepts in existing and future traction motors is presented and the cooling approaches are compared. The following literature review compiles geometry-based calculation formulas of the different mechanisms of cooling heat transfer applied in motor-technology. Furthermore general heat transfer phenomena appearing in electric traction motors are reviewed and compiled for easy access. Various specifically relevant aspects, including rotor shaft cooling, different spray cooling concepts, different air convection phenomena, bearing heat transfer and the stator-housing-contact, are examined in more detail. For validation of the review result, based on a well-known motor design a thermal analysis and comparison of the different cooling methods is carried out. Modeling is done with a lumped parameter thermal networks (LPTN). The paper concludes demonstrating the advantages and disadvantages of the different cooling concepts based on the collection of modeling data.
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