Wave logger pro

Signals of the voltage, current and force were sent to a PC through an I/O board (MF644, Humusoft, Prague, Czech Republic). with MATLAB R2020a (version 9.9.01467702, MathWorks, MA, USA) and Simulink (version 10.2, MathWorks) were installed on the PC. A strain gauge sensor (LSM-50K-B, MinebeaMitsumi, Nagano, Japan) was set on top of the syringe piston. The force signal was also sent to the I/O board via a strain amplifier (DPM-951A, Kyowa Electronic Instruments, Tokyo, Japan). A voltage divider using 1 MΩ with 2, 5 and 10 MΩ serially connected resistances which were selected according to the measured voltage range was employed. The current was calculated by the slope of the voltage stored in a capacitor (200 μF) during the experimenter’s foot pressing. For the for press unit, a data logger (NR-600, Keyence, Osaka, Japan) with a high-speed analog measurement system (NR-HA08, Keyence) and software (WAVE LOGGER PRO (version R4.02.00), Keyence) were used for recording. The data were recorded at 1 ms time intervals.

The viability of larvae was measured with an electrical signal collector every 30 min for 8 h. To obtain the DC voltage signal (waveform data) with the microdevice, a data logger (NR2000, Keyence) with a high-speed analog measurement system (NR-HA08, Keyence) and software (WAVE LOGGER PRO, Keyence) was used with a sampling rate of 1 kHz.

To measure the contractile force, a strain measurement system (NR-ST04 and NR-600, Keyence, Osaka, Japan) and interfaced software (WAVE LOGGER PRO, Keyence) were used. The time resolution was set as 1 ms. The strain was measured by using a strain gauge (KFW-5-120-C1-11, Kyowa, Chofu, Japan). All experiments were carried out at room temperature.