Sample holder

A sample holder comprising:

• an upper layer;
• a lower layer;
• a middle layer between the upper and lower layers, wherein the middle layer is bonded to the upper layer and the lower layer;
• and
• a sample chamber formed by a through-hole in the middle layer, covered at its upper extent by a portion of the bottom surface of the upper layer, and at its lower extent by a portion of the top surface of the lower layer,
• wherein a top periphery of the sample chamber is defined by edges of the sample chamber which bound the upper extent of the sample chamber,
• and wherein at least part of the bottom surface of the upper layer overlapping a portion of the top periphery of the sample chamber comprises a hydrophobic surface, wherein the hydrophobic surface is sufficiently hydrophobic that a contact angle of a water droplet on the hydrophobic surface would exceed 110°, such that in use, the hydrophobic surface acts to seal the sample in the sample chamber, without a continuous bond between the upper layer and middle layer where the bottom surface of the upper layer overlapping the portion of the top periphery of the sample chamber comprises the hydrophobic surface.