humidifier RH sensor

IN signal from lock-in amp 1 IN reference from fuctionon generator square wave synch pulse at 1Hz Function generator square wave 0-10V Recording oscilloscope lock-in 1 lock-in 2 OUT square wave -10 to +10V output to GFET Vgs and to oscilloscope Locked-in delta Thz signal absolute Thz signal IN CH1 from lock-in 1 absolute THz signal IN CH2 from 1Hz square wave function generator (OUTPUT +/- 10V) IN signal from THz Schottky detector? OUT to oscilloscope and lock-in 2 IN reference from 1kHz 101GHz driver IN reference from 101GHz driver 1 kHz Synch pulse OUT to lock-in 2 IN signal from THz Schottky detector.

~+/-10V from function generator ~10mV Why is the CH2 square wave function ~18.6V? We used 0-10V amplitude from function generator. What is the significance of CH1 frequency number seen at bottom of oscilloscope trace? It varies between 0.3Hz and 2.1Hz over the 35 tracings we saved through the day. What is the significance of the phase relationship between the square function 0-10V and the THz transmission signal? The ‘absolute’ 101GHz signal is seen in lock-in amp 1 and is from Schottky detector. What frequency is this lock-in amp 1 locked to? 1kHz. It is the generator modulation frequency of the Gunn diode driver (101GHz at 1kHz)? I wrote down lock-in amp 2 readout = 11.6mV - this seems to agree with this tracing right? +/- 10V square wave This can be due to the noise. Elliott says none

dashes indicate data points taken at 93% RH, condensing on GFET all delta THz numbers have been scaled to fit on plot, delta THz (lockin 1Hz) ranges from 9.9 – 26mV while ‘absolute’ THz is shown uncorrected in this plot in V All of these voltages are arbitrary representations of THz transmission add water 100uL blow off add buffer 100uL blow off rinse 400uL ddH2O blow add 100uL of 0.1nM DNA O cut THz power by ‘exactly ½’ to stop overflow of lockin1 values after this point are normalized by 2x multiply rinse 400uL ddH2O blow add 100uL of 2nM DNA O rinse 400uL ddH2O 15mins blow Dashes indicate data points taken at 20% RH. Condensed water rapidly evaporates from GFET (surprisingly quickly)

silicon oxide, OTS, no benzimidizole measured at WSU pre-expt. and post expt. Vds = 0.05V Vgs (volts) Ids (amps) Vgs (volts) Ids (amps) Vds = 0.05V before experimentafter experiment Each Vgs sweep is forward only, colors represent sweeps taken at the times indicated below charts.

silicon oxide, OTS, no benzimidizole measured With Vds = 0.0V, Vds shorted: Igs at 20Vgs 20Gohm When measured at sweeping Vgs (chart below left), Igs was still small but fluctuated +/- 300nA around 0.0A Vds = 0.05V Vds = 0.001V Vds = 0.1V Vds = 0.01V Vds = 0.0(Vds shorted) Vgs (volts) Ids (amps) Vds = 0.0(Vds shorted) gate leak or Igs (amps) Vgs (volts) Each Vgs 1V step takes ~250msec solid lines fwd. sweep dashed lines rev. sweep sweep number within each set 1-blue 2-cyan gate current, fluctuations but no hysteresis in fwd vs rev sweeps

silicon oxide + 10nm aluminum oxide, no OTS, no benzimidizole measured With Vds = 0.0V, Vds shorted: Igs at 20Vgs 20Gohm When measured at sweeping Vgs (chart below left), Igs was still small but fluctuated up to +150nA on forward sweep and -150nA on reverse sweep, hysteresis shown in inset of gate current chart Vds = 0.05V Vds = 0.001V Vds = 0.1V Vds = 0.01V Vds = 0.0(Vds shorted) Each Vgs 1V step takes ~250msec solid lines fwd. sweep dashed lines rev. sweep sweep number within each set 1-blue 2-cyan Vgs (volts) Ids (amps) Vds = 0.0 (Vds shorted) gate leak or Igs (amps) Vgs (volts) gate current hysteresis seen in fwd vs rev sweeps

Phi silicon oxide + 10nm aluminum oxide, no OTS, no benzimidizole measured THIS DEVICE IS AS DELIVERED BY PHI Vds = 0.05V Each Vgs 1V step takes ~250msec solid lines fwd. sweep dashed lines rev. sweep sweep number within each set 1-blue 2-cyan Vgs (volts) Ids (amps) Phi silicon oxide, OTS, no benzimidizole measured THIS DEVICE HAD BEEN TREATED WITH DNA AND BUFFER AND MEASURED AT WSU Vds = 0.05V Vgs (volts) Ids (amps) ALTHOUGH QUANTITATIVELY DIFFERENT, THESE 2 GFETS BEHAVE, QUALITATIVELY, VERY SIMILARLY

relative humidity 93% condensing on GFET 20% rapidly evaporates from GFET (surprisingly fast) all delta THz numbers have been scaled to fit on plot, delta THz (lockin 1Hz) ranges from 9.9 – 26mV while ‘absolute’ THz is shown uncorrected in this plot in V add water 100uL blow off add buffer 100uL blow off rinse 400uL ddH2O blow add 100uL of 0.1nM DNA O cut THz power by ‘exactly ½’ to stop overflow of lockin1 rinse 400uL ddH2O blow add 100uL of 2nM DNA O rinse 400uL ddH2O 15mins blow

dashes indicate data points taken at 93% RH, condensing on GFET all delta THz numbers have been scaled to fit on plot, delta THz (lockin 1Hz) ranges from 9.9 – 26mV while ‘absolute’ THz is shown uncorrected in this plot in V All of these voltages are arbitrary representations of THz transmission add water 100uL blow off add buffer 100uL blow off rinse 400uL ddH2O blow add 100uL of 0.1nM DNA O cut THz power by ‘exactly ½’ to stop overflow of lockin1 values after this point are normalized by 2x multiply rinse 400uL ddH2O blow add 100uL of 2nM DNA O rinse 400uL ddH2O 15mins blow Dashes indicate data points taken at 20% RH. Condensed water rapidly evaporates from GFET (surprisingly quickly)