Interdigitated impedance electrodes of miniaturized impedance sensors

An apparatus, comprising:

• a band configured to extend at least partially around a body part of a user, the body part comprising a dermal layer and a subdermal feature adjacent to the dermal layer within the body part;
• a user interface coupled to the band;
• a processing device coupled to the band;
• a miniaturized impedance sensor integrated into the band and positioned in the band to be pressed against the dermal layer adjacent to the subdermal feature, the miniaturized impedance sensor comprising:
• a first set of a set of interdigitated fingers of miniaturized electrodes configured to transmit an electric signal into the body part as the user wears the band, wherein the first set of miniaturized electrodes is positioned in the band to straddle the subdermal feature as the user wears the band;
• and
• a second set of a set of interdigitated fingers of miniaturized electrodes configured to receive the electric signal through the body part as the user wears the band, wherein:
• the second set of miniaturized electrodes is positioned in the band to straddle the subdermal feature as the user wears the band;
• and
• an electrical circuit embedded in the band interconnecting the user interface, the processing device, or the miniaturized impedance sensor;
• and
• wherein each miniaturized electrode comprises an array of a first miniaturized electrode pillar and a second miniaturized electrode pillar, the first miniaturized electrode pillar comprising a first height greater than a first length or a first width and a first contact surface of the first miniaturized electrode pillar defined by the first length and the first width of the first miniaturized electrode pillar, the second miniaturized electrode pillar comprising a second height greater than a second length or a second width and a second contract surface of the second miniaturized electrode pillar defined by the second length and the second width of the second miniaturized electrode pillar.

An apparatus, comprising:

• a band configured to extend at least partially around a body part of a user, the body part comprising a dermal layer;
• a user interface coupled to the band;
• a processing device coupled to the band;
• a miniaturized impedance sensor integrated into the band and positioned in the band to be pressed against the dermal layer adjacent to a subdermal feature, wherein:
• a first set of miniaturized electrodes is configured to transmit an electric signal into the body part as the user wears the band;
• and
• a second set of miniaturized electrodes is configured to receive the electric signal through the body part as the user wears the band;
• wherein each miniaturized electrode comprises an array of a first miniaturized electrode pillar and a second miniaturized electrode pillar, the first miniaturized electrode pillar comprising a first height greater than a first length or a first width and a first contact surface of the first miniaturized electrode pillar defined by the first length and the first width of the first miniaturized electrode pillar, the second miniaturized electrode pillar comprising a second height greater than a second length or a second width and a second contract surface of the second miniaturized electrode pillar defined by the second length and the second width of the second miniaturized electrode pillar;
• an electrical circuit embedded in the band interconnecting the user interface, the processing device, or the miniaturized impedance sensor;
• and
• at least one interstitial filler distributed between the first and second sets of miniaturized electrodes and the first and second miniaturized electrode pillars of each miniaturized electrode set.