N. Heidrich

Diamond electro-optomechanical resonators integrated in nanophotonic circuits

Diamond integrated photonic devices are promising candidates for emerging applications in nanophotonics and quantum optics. Here, we demonstrate active modulation of diamond nanophotonic circuits by exploiting mechanical degrees of freedom in free-standing diamond electro-optomechanical resonators. We obtain high quality factors up to 9600, allowing us to read out the driven nanomechanical response with integrated optical interferometers with high sensitivity. We are able to excite higher order mechanical modes up to 115 MHz and observe the nanomechanical response also under ambient conditions.

Enhanced mechanical performance of AlN/nanodiamond micro-resonators

Micro electromechanical systems are a matter of intense research pursuing to replace silicon and III–V semiconductor-based components in prospective radio frequency communication devices. Due to their unique material properties, microstructures combining doped nano-crystalline diamond (NCD) and AlN thin films are promising for piezo-actuated microsystems in order to increase operating frequencies. In this work, single and doubly clamped unimorph NCD-on-AlN micro-resonators were fabricated and then characterized by laser vibrometry towards their flexural resonant frequencies in the range of 0.1–20 MHz to deduce their mechanical properties. Enhancements in the structural properties of an AlN piezo-actuator united with an advanced elasticity of nano-diamond electrode lead to superior mechanical parameters of the resulting unimorphs. These allow for the fabrication of flexural resonant microsystems with a potential to extend the operating frequencies well above 1 GHz.

Electrostatically coupled vibration modes in unimorph complementary microcantilevers

To extend the tuning capabilities of radio frequency devices, coupled microelectromechanical systems are often employed. In this letter, we demonstrate piezoelectrically actuated, electrically tuneable resonator systems based on coupled micromechanical oscillators operating in a flexural vibration mode. The substantial enhancement in electrostatic coupling was achieved due to the implementation of lateral nanogaps of 100-200 nm between single resonator bars. This allows for resonator synchronization and precise system frequency tuning by over a factor of two, relative to its initial value. Additionally, a simple electro-mechanical model has been developed to describe the dynamic behavior of the electrostatically coupled oscillators.

Biocompatible AlN-based piezo energy harvesters for implants

In this work, we show that thin biocompatible AlN films reveal a stable, frequency independent piezoresponse demonstrating a good applicability for implantable micro-generators. It was demonstrated that although more power is generated by resonant (tensile stressed) systems, e.g. cantilevers and planar membranes, the non-resonant (compressive stressed) systems, e.g. corrugated membranes, are preferable for this purpose due to the generation of sufficient power at low-frequency aperiodic vibrations and at very low accelerations.

Nano-diamond based spheres for radio frequency electromechanical resonators

In this work, we report on the electro-mechanical studies of high-Q spherical oscillators designed to operate in radio-frequency circuits. Resonating composite spheres, consisting of a silicon core and a thick nanodiamond shell, were studied by laser vibrometry in order to obtain mechanical quality factors and identify the resonant frequencies and eigenmodes of the system. Finite element method simulations were used to analyze and confirm the experimental data. Additionally, reflection/transmission measurements were carried out on capacitively coupled spheres in order to evaluate the electrical parameters of the system. The main aim of these investigations was to evaluate the potential of diamond-based spherical resonators to be used in modern communication devices.