Rheovant
RHEOVANT
Instrumentation / Flow / Analysis
Rheovant

Built to measure.
Built to hold a current.

An applied-science studio making affordable laboratory instruments, continuous-flow reactors and the analysis software that goes with them.

See the instrumentsHow it works
Scroll to step inside
01 / WHAT IT DOES

Four things,
done properly.

01

Constant-current control

Three independent channels drive current directly, so deposition and cycling run at a set current instead of a set potential.

02

Symmetrical AC sensing

Alternating excitation at 1–5 kHz keeps net DC current at the electrode near zero, which is what suppresses polarisation drift.

03

Continuous-flow synthesis

Millifluidic and tubular reactors for Ni-BDC and Cu-BDC, replacing batch autoclave runs with a controlled residence time.

04

Kinetic deconvolution

Dunn's method separates surface-controlled charge from diffusion-controlled charge: i(V) = k1·v + k2·v^(1/2).

02 / INSTRUMENTATION

Hardware, with the
status stated plainly.

Nothing here is for sale. These are research builds and design targets. Each row is tagged so you can see what has actually been bench-tested versus what is still a specification on paper.

GS-350

RV-GS350
built

Three-channel galvanostatic controller for electrodeposition and supercapacitor cycling, built to cover the constant-current work a potential-only potentiostat cannot do.

Channels
3, independentbuilt
Current range
0–56 mA per channelbuilt
Rated ceiling
50 mAbuilt
Compliance voltage
10–14 V DCbuilt
Bench supply
GW Instek GPS-3030Dbuilt
Terminals
Dedicated anode / cathode, 4 mmbuilt

Built and bench-verified in Bandung. No published noise or accuracy figure yet — measurement is pending.

4-Electrode Conductivity

RV-COND-4E
design target

Liquid conductivity and salinity front-end using symmetrical AC excitation to avoid the polarisation drift that degrades simple two-electrode probes.

Electrodes
4 graphite, C-V-V-C arraytarget
Excitation
1–5 kHz symmetrical ACtarget
ADC
ADS1115, 16-bit differentialtarget
Temperature
DS18B20, referenced to 25 °Ctarget
Controller
ESP32, USB-C / WebSerialtarget
Probe material
Graphite (platinum excluded on cost)target

Design target, not yet built. Prototype budget estimated Rp350,000–685,000. Values are design intent, not measurements.

Rheovant Stat

RV-STAT01
roadmap

Companion potentiostat / cycler core, designed to add galvanostatic charge–discharge to a bench that already has a commercial potentiostat.

Controller
ESP32plan
Supply
±12 V dual-rail DC-DCplan
DAC
MCP4725, 12-bitplan
ADC
ADS1115, 16-bitplan
Amplifiers
TL072 / TL071plan
Techniques
CV, GCD, CA, LSVplan

Architecture defined; hardware not yet built. Treated as a roadmap item.

03 / RESEARCH

The work behind
the instruments.

FLOW

Continuous-flow MOF synthesis

Millifluidic and tubular reactors for Ni-BDC and Cu-BDC, replacing batch autoclave runs with a controlled residence time and a narrower size distribution.

Graduate research, Institut Teknologi Bandung

LSPR

Photothermal intensification

Plasmonic nanomaterials inside flow channels convert light to localised heat at the reaction interface, cutting the thermal lag of an external bath.

Localised surface plasmon resonance

KINETICS

Charge-storage analysis

Dunn's method separates surface-controlled from diffusion-controlled charge, so a result reports which mechanism actually limits the electrode.

i(V) = k1·v + k2·v^(1/2)

Research descriptions are summaries of ongoing work. No results, yields or performance figures are published here until they are measured and reproducible.

04 / METHOD

Which mechanism
actually limits the electrode.

Dunn's method separates surface-controlled charge from diffusion-controlled charge by fitting i(V) = k1·v + k2·v^(1/2) across a set of scan rates.

illustration · not measured data

Coefficients are illustrative. This demonstrates the method; it is not a fit to real samples.

0.00.30.6E vs Ag/AgCl (V)+i−i
Scan ratemV/s
Modelled split at 50 mV/s
Surface-controlled35%
Diffusion-controlled65%
Window
0.0–0.6 V
Peak index
603

Higher scan rates leave less time for diffusion into the bulk, so the modelled surface fraction rises. That trend is the point of the method; the specific percentages are illustrative.

05 / QUESTIONS

Straight answers,
including the awkward ones.

It is positioned as an independent applied-science studio rather than a personal consultancy. Gerald Arya Dewangga is the founder and principal engineer. Trademark clearance is still pending, so this is a controlled rollout — no commercial launch has been claimed.

07 / FOUNDER

Rheovant is the studio.
Gerald is the engineer.

Gerald Arya Dewangga, S.Si. is a materials chemist and instrumentation engineer working in inorganic and physical chemistry at Institut Teknologi Bandung.

His research covers continuous-flow synthesis of Metal-Organic Frameworks, photothermal intensification by localised surface plasmon resonance, and the electrochemical kinetics of charge storage. The instruments on this site exist because that work needed measurements the available equipment could not make — a constant-current source across three cells at once, or conductivity sensing that does not drift as the electrode polarises.

Rheovant is positioned as an independent studio rather than a personal consultancy: the work is meant to outlive any single thesis.

“Capability is not bought off the shelf. It is understood, designed, calibrated and built.”

Working principles

  • 01

    Measured, not claimed

    A specification is published only after it has been bench-tested. Until then it is labelled a design target.

  • 02

    Affordable by design

    Graphite instead of platinum, an external ADC instead of a marginal one. Accuracy comes from topology, not from a bigger budget.

  • 03

    Full stack, one bench

    Wet chemistry, analogue front-end, firmware and the analysis software are all built in-house, so the layers actually fit.

  • 04

    Reproducible

    Residence times, calibration constants and analysis code are recorded, so a result can be repeated rather than trusted.

06 / CONTACT

Open to
collaboration.

Academic collaboration, instrument co-development and laboratory data-acquisition work. If you are describing a measurement problem, include the parameters — it makes the first reply useful.

gerald.arya154@gmail.com
Bandung, West Java, Indonesia

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