Journal: Soft Robotics

Article Title: Soft Radio-Frequency Identification Sensors: Wireless Long-Range Strain Sensors Using Radio-Frequency Identification

doi: 10.1089/soro.2018.0026

Figure Lengend Snippet: (a) Schematic diagram of the stretchable microfluidic sensor. Galinstan is enclosed in Ecoflex substrate while an RFID chip is bonded on a piece of aluminum foil, which is inserted in the channels. Detailed and cross-section figures of the part near RFID chip are presented. Directions of x , y , and z axes are indicated. (b) Initial state of the antenna when it is not stretched. The effective antenna length on the x -direction and y -direction is defined as l x and l y , respectively. Notice: the electrical length of the entire antenna is l x + 10 l y + l m . The nonsymmetric part, l m , is used for fine impedance matching between the antenna and the RFID chip. (c) When the soft antenna is stretched, the effective antenna length on the x -direction and y -direction is defined as l x + Δ l x and l y + Δ l y , respectively. RFID, radio-frequency identification.

Article Snippet: We made small incisions in the center of the thin Ecoflex layer to embed the RFID chip; the RFID chip (Monza R6; Impinj) was bonded on an Aluminum film with a bonding machine (FB-300 manual RFID wrapping machine) and inserted in the channels.

Techniques:

Journal: Soft Robotics

Article Title: Soft Radio-Frequency Identification Sensors: Wireless Long-Range Strain Sensors Using Radio-Frequency Identification

doi: 10.1089/soro.2018.0026

Figure Lengend Snippet: (a) Equivalent circuit of the RFID chip and the transporter antenna. Z a is the total impedance of the transport antenna, whereas Z c is impedance of the RFID chip. (b) Schematic diagram of T-matching for a dipole antenna. The l represents the length of the original dipole antenna. This antenna is connected at the center to a short second dipole. The close distance between matching stub and the original antenna is b , whereas w and w' are the widths of the original dipole antenna and the mating stub, respectively. (c) Equivalent circuit at the source point of the dipole antenna after T-matching. Z' a is the impedance of the first dipole antenna without T-matching, whereas Z t is the impedance that the matching stub created. The α in the ratio is the current division factor between the two connectors.

Article Snippet: We made small incisions in the center of the thin Ecoflex layer to embed the RFID chip; the RFID chip (Monza R6; Impinj) was bonded on an Aluminum film with a bonding machine (FB-300 manual RFID wrapping machine) and inserted in the channels.

Techniques:

Journal: Soft Robotics

Article Title: Soft Radio-Frequency Identification Sensors: Wireless Long-Range Strain Sensors Using Radio-Frequency Identification

doi: 10.1089/soro.2018.0026

Figure Lengend Snippet: Fabrication process and prototype of the stretchable microfluidic sensor (RFID tag antenna). (a) Cut the sensor profile on a piece of self-adhesive vinyl attached on an acrylic substrate. Notice: the red and pink parts are a same piece of vinyl. Two different colors are used here to show the laser-cut profile clearer. (b) The unwanted part of vinyl was peel off, a 2 mm-thick acrylic frame was stuck on the substrate to form a soft-lithography mold. (c) Uncured Ecoflex with a controlled height of 2 mm was poured into the soft-lithography mould. (d) The casted piece of Ecoflex was sealed with another 0.15 mm Ecoflex film, and the RFID chip bonded on aluminum film was inserted into the channels. (e) Two needles were used to inject Galinstan into the channel. (f) Photograph of the final prototype.

Article Snippet: We made small incisions in the center of the thin Ecoflex layer to embed the RFID chip; the RFID chip (Monza R6; Impinj) was bonded on an Aluminum film with a bonding machine (FB-300 manual RFID wrapping machine) and inserted in the channels.

Techniques: Adhesive

Journal: Soft Robotics

Article Title: Soft Radio-Frequency Identification Sensors: Wireless Long-Range Strain Sensors Using Radio-Frequency Identification

doi: 10.1089/soro.2018.0026

Figure Lengend Snippet: (a) We used the Voyantic Tagformance system to measure characteristics of the proposed antenna. This measurement system sends input signals to the tag antenna with transmitted power. The power received on tag is the transmitted power minus cable loss and free space loss. RFID chip in the tag antenna receives the input signals, absorbs energy in the signals, and then sends backscattered signals back to the measurement system. According to the results of the measurement system, we can know the resonant frequency and the theoretical reading range of the tag antenna, as well as the phase of the backscattered signals. We affixed the two edges of the tag antenna with clips made of rigid foam. To stretch the tag antenna and hold its position for measurement, we stuck grip tape on the surface of the foam clips and on the measurement platform. (b) Experimental setup for measurement of the permittivity of Ecoflex 00-50 with the Agilent 85070E dielectric probe kit system. (c) Photograph of the experimental setup of the soft antenna and the Voyantic Tagformance system.

Article Snippet: We made small incisions in the center of the thin Ecoflex layer to embed the RFID chip; the RFID chip (Monza R6; Impinj) was bonded on an Aluminum film with a bonding machine (FB-300 manual RFID wrapping machine) and inserted in the channels.

Techniques: