• Journal of Sensor Science and Technology
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• v.32 no.6
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• pp.418-424
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• 2023

Natural killer (NK) cells play a crucial role in combating infections and tumors. However, their therapeutic application in solid tumors is hindered by challenges, such as limited lifespan, tumor penetration, and delivery precision. Our research introduces a novel ultrasonic actuation technique to navigate NK cells more effectively in the vascular system, particularly at vessel bifurcations where targeted delivery is most problematic. We use a hemispherical ultrasonic transducer array that generates phase-modulated traveling waves, focusing on an ultrasound beam to steer NK cells using blood-flow dynamics and a focused acoustic field. This method enables the precise obstruction of non-target vessels and efficiently directs NK cells toward the tumor site. The simulation results offer insights into the behavior of NK cells under various conditions of cell size, radiation pressure, and fluid velocity, which inform the optimization of their trajectories and increase targeting efficiency. The experimental results demonstrate the feasibility of this ultrasonic approach for enhancing NK cell targeting, suggesting a potential leap forward in solid tumor immunotherapy. This study represents a significant step in NK cell therapeutic strategies, offering a viable solution to the existing limitations and promising enhancement of the efficacy of cancer treatments.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.1
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• pp.23-31
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• 2002

We proposed a concept of a desktop micro device factory for visually servoed teleoperated microassembly assisted by a virtual reality (VR) interface. It is composed of two micromanipulators equipped with micro tools operating under a light microscope. First a manipulator, control method for the micro object to follow a planned trajectory in pushing operation is proposed undo. vision based-position control. Then, we present the cooperation control strategy of the micro handling operation under vision-based force control integrating a sensor fusion framework approach. A guiding-system based on virtual micro-world exactly reconstructed from the CAD-CAM databases of the real environment being considered is presented for the imprecisely calibrated micro world. Finally, some experimental results of microassembly tasks performed on millimeter-sized components are provided.

• Journal of Mechanical Science and Technology
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• v.18 no.5
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• pp.789-797
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• 2004

The nanoscale sensing and manipulation have become a challenging issue in micro/nano-robotic applications. In particular, a feedback sensor-based manipulation is necessary for realizing an efficient and reliable handling of particles under uncertain environment in a micro/nano scale. This paper presents a piezoresistive MEMS cantilever for nanoscale force measurement in micro robotics. A piezoresistive MEMS cantilever enables sensing of gripping and contact forces in nanonewton resolution by measuring changes in the stress-induced electrical resistances. The calibration of a piezoresistive MEMS cantilever is experimentally carried out. In addition, as part of the work on nanomanipulation with a piezoresistive MEMS cantilever, the analysis on the interaction forces between a tip and a material, and the associated manipulation strategies are investigated. Experiments and simulations show that a piezoresistive MEMS cantilever integrated into a micro robotic system can be effectively used in nanoscale force measurements and a sensor-based manipulation.