Directed nanoparticle self‐organization and two‐photon polymerization are combined to enable three‐dimensional soft‐magnetic microactuators with complex shapes and shape‐independent magnetic properties. Based on the proposed approach, single and double twist‐type swimming microrobots with programmed magnetic anisotropy are demonstrated, and their swimming properties in DI‐water are characterized. The fabricated devices are actuated using weak rotating magnetic fields and are capable of performing wobble‐free corkscrew propulsion. Single twist‐type actuators possess an increase in surface area in excess of 150% over helical actuators with similar feature size without compromising the forward velocity of over one body length per second. A generic and facile combination of glycine grafting and subsequent protein immobilization exploits the actuator's increased surface area, providing for a swimming microrobotic platform with enhanced load capacity desirable for future biomedical applications. Successful surface modification is confirmed by FITC fluorescence.

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We present the design, fabrication, and characterization of an in-plane vibration sensor with frequency selective displacement amplification and differential capacitive read-out. The mechanical structure is based on six resonators with decreasing stiffness coupled in-plane. A differential capacitance attached to the last mass serves as electrical read out. Finite element and lumped element models are both presented. The devices were fabricated in a single mask silicon on insulatorbased process. The mechanical, as well as the capacitive transfer function and the pressure dependence, have been investigated experimentally and compared with simulations. The measured mean (minimum) amplification was 24 dB (16 dB) over a bandwidth of 10 kHz (3-13 kHz). While the mean amplification is pressure dependent, the minimum amplification and bandwidth show a less than 10% decrease over a wide pressure range from 6.3 to 64 mbar. The pressure dependent measurements also show that the minimum amplification is independent of the Q factor of the modes down to values of Q∼10. Both simulation and experiment show that the off-axis modes occur outside the bandwidth of the device. Along with the low cross-sensitivity of the capacitive readout (0.06%), this provides good axis selectivity despite the high number of degrees of freedom. The device can be used for detection of broadband vibration signals, e.g., for structural monitoring of infrastructure such as bridges and pipelines.

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