## 1 Introduction  
The use of embroidered conductive thread to produce a range of radio frequency antenna systems has become popular since the late 1990s when conductive fabrics began to be used for wearable systems. Initially used for Direct Current to low frequency and for shielding applications [1], their obvious potential for higher frequency systems became clear in the early part of this century [2]. These systems are now becoming commonplace for use as GPS, Mobile Phone and Radio Frequency Identification (RFID) [3; 4; 5; 6; 7] antennas to which they are ideally suited. It should be noted however that regular washing of such conducting yarns does lead to degradation in the electrical properties [8]. An application which has, until now, remained unexplored is the use of conductive fiber coils in magnetic resonance imaging.  
Pulsed nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are well established techniques most commonly associated with large scanners. In recent years the availability of low field strength (<1 Tesla) unilateral (single-sided) NMR probes [9; 10; 11; 12], based on simple rare earth permanent magnets, has been accompanied by an increase in the number of low cost NMR consoles (the electronics used to drive them). Applications have also diversified as a result of more affordable hardware [13; 14; 15]. All pulsed magnetic resonance systems face the same challenge: a large power is needed to excite the sample (1-1000 W) whilst the collected signal is typically less than a micro-Watt. Figure 1 shows the elements required to obtain an NMR signal from a sample. For transmission, RF pulses are generated at low power and amplified to the required level to excite the sample when delivered to the NMR probe (containing an impedance matching circuit and sample coil). The small radio frequency signal produced by the sample is then induced into the same (or a closely placed) coil which is connected to a low noise preamplifier that produces a signal suitable for the RF detection stage allowing digital or analogue processing. A duplexer is used as a transmit receive switch to protect the preamp during transmission and to reduce noise by isolating the transmitter during reception.  
The NMR probe usually consists of a coil with a tuning capacitor in parallel with the coil and, a matching capacitor in series with the coil, allowing the probe to apply and receive high frequency  
Figure 1: Schematic diagram of a typical pulsed nuclear magnetic resonance (NMR) system showing components and impedance matching circuit.  
energy to and from a sample of interest in a magnetic field [16,17]. This is usually achieved with copper coils placed around the sample in rigid housings. Most often a single coil is used to both excite the sample and to collect the resultant signal, whilst for more sensitive studies separate coils are used. These can be made of copper on flexible substrates in order to decrease the separation between the sample and the coil as proximity and conformity of the coil are critical parameters in maximising the SNR. In this paper we present a fundamental demonstration of the principles of using an embroidered conductive fabric coil for magnetic resonance.