Nonlinear and smart metamaterials useful to change resonance frequencies

A method comprising:

• providing a nonlinear resonator and a second resonator, wherein:
• the nonlinear resonator is controllably configurable into an isolation configuration having an isolation mode resonant frequency, and a reception configuration having a reception mode resonant frequency distinct from the isolation mode resonant frequency, and wherein
• the second resonator has a second resonant frequency equal to the reception mode resonant frequency;
• in a first mode, configuring the nonlinear resonator into the isolation configuration, such that the nonlinear resonator is substantially communicatively isolated from the second resonator so as to isolate the nonlinear resonator from a signal on the second resonator, and to isolate the second resonator from another signal on the nonlinear resonator;
• and
• in a second mode, configuring the nonlinear resonator in the reception configuration such that the nonlinear resonator is configured for resonant communication with the second resonator;
• wherein resonant coupling between the second resonator and the nonlinear resonator in the isolation configuration is at least 9 dB less than resonant coupling between the second resonator and the nonlinear resonator in the reception configuration.

A signal magnifying accessory for use within a bore of an MM machine, the Mill machine having a transmitting coil disposed to transmit, to a specimen in the bore, an excitation signal having a transmission frequency in a transmitting mode, and a reception coil disposed to receive, from the specimen, a response signal having a response frequency in a receiving mode, the accessory comprising:

• a resonator array comprising a plurality of metamaterial resonators, each of the metamaterial resonators having a resonant frequency, the metamaterial resonators disposed to inductively couple to one another in response to an applied electromagnetic signal;
• a non-linear control resonator comprising:
• a resonator coil;
• and
• a controllable impedance coupled to the resonator coil wherein the resonator coil comprises a first end and a second end, and the controllable impedance is electrically coupled between the first end and the second end,
• the control resonator having a first resonant frequency when the controllable impedance is in a first impedance state, and a second resonant frequency when the controllable impedance is in a second impedance state;
• a spacer layer disposed between the array of resonators and the non-linear resonator, the spacer layer defining a gap (d) between the array of resonators and the non-linear resonator;
• and
• the resonator coil and the controllable impedance selected so that the control resonator is configured (i) to produce, in concert with the resonator array when the MRI machine is in the transmitting mode, a first array resonant frequency offset from the transmission frequency;
• and (ii) to produce, in concert with the resonator array when the MM machine is in a receiving mode, a second array resonant frequency equal to the response frequency, so as to magnify the response signal.

A method of amplifying a response signal from a specimen in the bore of an Mill machine, the Mill machine configured to transmit a radio frequency excitation signal to the specimen, the radio frequency excitation signal configured to elicit, from the specimen, the response signal, the method comprising:

• providing, in the bore of the MRI machine having a working frequency, a controllable array assembly, the controllable array assembly comprising:
• a resonator array comprising a plurality of metamaterial resonators configured to inductively couple to one another at the operating frequency of the MRI machine;
• and
• a nonlinear control resonator having a controllable impedance, the controllable impedance configured to change impedance in response to receipt by the controllable impedance of the radiofrequency excitation signal transmitted by the MRI machine;
• configuring the controllable array assembly into a passthrough mode when the MM machine is in a transmitting mode by receiving, at the controllable impedance, said radiofrequency excitation signal transmitted by the MM machine;
• and
• configuring the controllable array assembly into an amplifying mode when the MM machine is in a receiving mode.