Stretchable Tattoo-Like Heater With On-Site Temperature ... - PubMed

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Abstract

Wearable tissue heaters can play many important roles in the medical field. They may be used for heat therapy, perioperative warming and controlled transdermal drug delivery, among other applications. State-of-the-art heaters are too bulky, rigid, or difficult to control to be able to maintain long-term wearability and safety. Recently, there has been progress in the development of stretchable heaters that may be attached directly to the skin surface, but they often use expensive materials or processes and take significant time to fabricate. Moreover, they lack continuously active, on-site, unobstructive temperature feedback control, which is critical for accommodating the dynamic temperatures required for most medical applications. We have developed, fabricated and tested a cost-effective, large area, ultra-thin and ultra-soft tattoo-like heater that has autonomous proportional-integral-derivative (PID) temperature control. The device comprises a stretchable aluminum heater and a stretchable gold resistance temperature detector (RTD) on a soft medical tape as fabricated using the cost and time effective "cut-and-paste" method. It can be noninvasively laminated onto human skin and can follow skin deformation during flexure without imposing any constraint. We demonstrate the device's ability to maintain a target temperature typical of medical uses over extended durations of time and to accurately adjust to a new set point in process. The cost of the device is low enough to justify disposable use.

Keywords: epidermal electronics; feedback control; temperature sensor; wearable heater.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1

Figure 1

( a ) Fabrication process…

Figure 1

( a ) Fabrication process used for heater and resistance temperature detector (RTD),…

Figure 1 (a) Fabrication process used for heater and resistance temperature detector (RTD), shown for heater. Material is put on the thermal release tape (TRT) and cut with Silhouette cutter. TRT is heated, excess material is removed and remaining material is transferred to Tegaderm; (b) Complete device on tegaderm. Aluminum with blue polyimide backing forms the resistive heating element while Au/Cr 100/10 nm forms the resistance temperature detector.
Figure 2

Figure 2

( a , b )…

Figure 2

( a , b ) Device conforms to hand and maintains its conformability…

Figure 2 (a,b) Device conforms to hand and maintains its conformability during opening and closing; (c,d) Infrared (IR) images of the device powered with proportional-integral-derivative (PID) control as the hand is opened and closed. The PID controller automatically adjusts power output so the hand does not overheat when it closes.
Figure 3

Figure 3

( a ) Circuit diagram…

Figure 3

( a ) Circuit diagram of set-up for calibration of RTD in situ.…

Figure 3 (a) Circuit diagram of set-up for calibration of RTD in situ. Heater is brought to different temperatures by adjusting Vin. Resistance and temperature are measured simultaneously using a digital multimeter (DMM) and IR camera, respectively; (b) Lateral heat distribution of heater. Blue, red and green lines on IR image mark the horizontal line across which temperature was measured for their respective red, blue and green plots. Temperature distribution is fairly uniform. Dotted purple line on IR image shows area that the IR camera calculated the average temperature for; (c) Average temperature of area marked by the dotted purple line in Figure 3b (top) and resistance of Au/Cr RTD as measured by DMM (bottom) each plotted across time as Vin was changed to 3.8 V, 4.5 V and finally 5.1 V; (d) The calibration curve for the RTD: ΔR/R0 of the RTD versus ΔT of the average temperature of the area around the RTD as marked by the dotted purple line in Figure 3b. The calibration constant, β, is marked and is equal to 0.000203.
Figure 4

Figure 4

( a ) COMSOL thermal…

Figure 4

( a ) COMSOL thermal simulation results (left: top view; right: 3D view);…

Figure 4 (a) COMSOL thermal simulation results (left: top view; right: 3D view); (b) Lateral heat distribution of heater. Blue, red and green lines on simulation image (left) mark the horizontal line across which temperature was collected for their respective red, blue and green plots; (c) Vertical heat distribution of skin from the black line on simulation image (right).
Figure 5

Figure 5

( a ) Circuit diagram…

Figure 5

( a ) Circuit diagram of set up for operating heater with PID…

Figure 5 (a) Circuit diagram of set up for operating heater with PID control. DMM measures resistance of RTD and feeds it into a computer with LabVIEW, The LabVIEW program calculates the temperature of the RTD using the RTD’s starting temperature, starting resistance and calibration constant. It then uses a PID algorithm to calculate the optimal duty cycle for PWM of the heater given the heater’s current temperature and the set point temperature for the heater. The LabVIEW program then uses the data acquisition unit (DAQ) to switch the relay on and off with the determined duty cycle, thus controlling how much total power is fed to the heater; (b) Temperature of the heater versus time measured with both the RTD and the IR camera as the heater is turned on at a set point of 38.5 °C and then turned off. Heater is able to maintain set point temperature for an extended period of time; (c) Temperature of the heater versus time measured with both the RTD and the IR camera as the set point of the heater is changed while the voltage remains constant. At 40 °C, 6.2 V is not sufficient for the heater to reach the set point, so the voltage is increased to 7 V, at which point the heater is able to reach and maintain a temperature of 40 °C.
Figure 6

Figure 6

( a ) Plot of…

Figure 6

( a ) Plot of heater temperature versus time as the set points…

Figure 6 (a) Plot of heater temperature versus time as the set points and voltages are changed, followed by a plot of the corresponding duty cycle versus time. The average of the steady state duty cycles marked 1, 2 and 3 were used to calculate the power densities plotted below marked 1, 2 and 3, respectively, at different temperatures; (b) The same plots as figure A except the heater is insulated with a piece of foam.
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References

    1. Petrofsky J., Berk L., Bains G., Khowailed I.A., Hui T., Granado M., Laymon M., Lee H. Moist heat or dry heat for delayed onset muscle soreness. J. Clin. Med. Res. 2013;5:416–425. doi: 10.4021/jocmr1521w. - DOI - PMC - PubMed
    1. Nadler S.F., Weingand K., Kruse R.J. The physiologic basis and clinical applications of cryotherapy and thermotherapy for the pain practitioner. Pain Physician. 2004;7:395–399. - PubMed
    1. Brosseau L., Yonge K., Welch V., Marchand S., Judd M., Wells G., Tugwell P. Thermotherapy for treatment of osteoarthritis. Cochrane Database Syst. Rev. 2003;4 doi: 10.1002/14651858.CD004522. - DOI - PMC - PubMed
    1. Lehmann J. Therapeutic Heat and Cold. 4th ed. Williams & Wilkins; Baltimore, MD, USA: 1990.
    1. Choi S., Park J., Hyun W., Kim J., Kim J., Lee Y.B., Song C., Hwang H.J., Kim J.H., Hyeon T., et al. Stretchable heater using ligand-exchanged silver nanowire nanocomposite for wearable articular thermotherapy. ACS Nano. 2015;9:6626–6633. doi: 10.1021/acsnano.5b02790. - DOI - PubMed
Show all 49 references

Grants and funding

  • N00014-16-1-2044/Office of Naval Research Young Investigator Award
  • BET1250659/National Science Foundation Grant

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