A DIY-compatible, low-cost method for producing conductive carbon electronics on Kapton tape using a desktop laser engraver.

LaserPecker 3 Kapton / polyimide Benchtop fabrication

Abstract

Background

Laser-induced graphene is a three-dimensional, porous carbon nanomaterial produced by irradiating carbon-rich precursors with a laser—typically a CO₂ laser—in ambient air. First demonstrated in 2014 at Rice University by Lin, Tour & co-workers, the photothermal process converts the sp³ carbon of polyimide directly into sp² graphene networks without additional chemical reagents [1]. The resulting porous film is bonded to the polymer substrate, so it can be patterned in a single, mask-free step by simply rastering the laser beam.

The dominant mechanism is photothermal conversion: laser absorption heats the polymer locally above its decomposition temperature, releasing nitrogen and oxygen while reorganizing the remaining carbon into defective, few-layer graphene sheets. By adjusting laser wavelength, fluence, scanning speed and atmosphere, the resulting morphology can be tuned from isotropic porous structures to anisotropic cellular or woolly fibers. This customization permits control of electrical conductivity, capacitance, wettability and surface area, yielding flexible electrodes with thicknesses on the order of tens of microns.

Applications in the literature

Because LIG can be produced on flexible polymer films in ambient air with no wet chemistry, it has become a platform material for low-cost electronics. Reported applications include in-plane microsupercapacitors with specific capacitances above 4 mF cm⁻² [1], electrochemical sensors for heavy metals and metabolites [2], strain and pressure sensors for rehabilitation monitoring [3], thermoelectric foams for self-powered sensing [4], and laser-healed conductive traces with improved crystallinity [5]. More recent work has also transferred LIG onto elastomers as thin as 6.7 µm for large-area electronic skins [6]. These diverse uses all exploit the same core advantage: a conductive, high-surface-area carbon layer generated in a single laser-writing step.

Experimental Methods

Substrate preparation

Kapton sheets were cut into 40 mm × 40 mm squares. Surfaces were mechanically abraded with fine sandpaper to promote graphene and porous-structure formation, then cleaned with ethanol to remove contaminants that could lead to inhomogeneous conversion.

Fabrication setup

After 5 minutes of air drying, each sample was secured with Kapton tape to the bottom plate of a LaserPecker 3 laser engraver. The print area was aligned to the top-left corner of the software preview.

Parametric screening

A series of laser passes were executed at varying depth/power percentages, focal distances, resolutions, and pass counts to identify the processing window that yields conductivity.

Process Parameters and Formulas

Table 1. Parameter Legend

Symbol	Description	Units / Remarks
P	Laser power	W
P(%)	Relative power setting	Fraction or %
β / βmax	Beam-width ratio	Dimensionless
f / #	Optical F-number	Dimensionless
h	Hatch spacing (line spacing)	µm (convert to mm for energy-density calculations)
Res	Resolution code	e.g., 1k, 2k, 4k
S	Scan speed	mm/s
Smax	Max scan speed at given resolution	mm/s
Depth(z)	Process depth / penetration	Reciprocal of Smax as written
Dep	Depth factor	Dimensionless
Ed	Areal energy density	J/mm²
D	Duty cycle	%

Table 2. Core Formulas

Category	Expression	Notes
Power scaling	P(%) = (β / βmax) · (f / #)	Annotated “pwr width (ns)”; pulse-width dependence is noted but unspecified.
Full-power reference	P(100%) = 1 W	100 % scale = 1 W.
Hatch spacing	h = (1 / Res) · 100 µm	—
Speed limits	Smax(1k) = 800 mm/s Smax(2k) = 400 mm/s Smax(4k) = 200 mm/s	Units: mm/s.
Depth (reciprocal)	Depth(z) = 1 / Smax(Res)	Written as a direct reciprocal; a proportionality constant may be required.
Depth factor	Dep = 100 / Res	Used in the LCD shortcut.
Energy density (full)	Ed = P / (S · h)	Use consistent units: P [W], S [mm/s], h [mm].
Energy density (LCD)	Ed = P(%) · Dep	Shortcut valid when parameters are aligned to the full formula.

Results

Table 3. Parametric Screening Data

Depth (%)	Power (%)	Focus (mm)	Conductive	Resistance (Ω/mm²)	Passes	Resolution
100	80	13.8	No	—	1	1k
100	100	13.8	No	—	1	1k
100	100	14.5	No	—	1	1k
100	100	13.0	No	—	1	1k
100	100	14.8	No	—	1	1k
100	100	15.2	No	—	1	k
100	100	14.2	Yes	8	2	1k
20	100	14.2	Yes	20	2	4k

Discussion

The parametric sweep reveals that conductive traces were achieved only at a focal distance of 14.2 mm, using 2 passes at 1k resolution and 100 % power. At focal distances between 13.0 mm and 15.2 mm—regardless of power or depth percentage—no conductivity was observed with single-pass processing at 1k resolution. Sheet resistance values of 8 Ω/mm² and 20 Ω/mm² were recorded for 100 % and 20 % depth settings, respectively, indicating that once the focal window and resolution are correct, the depth percentage modulates the final resistance.

Conclusion

This note demonstrates a simple, DIY-compatible route for fabricating laser-induced graphene circuits on Kapton tape using a desktop laser engraver. By clarifying the relevant process parameters and formulas, and by identifying the critical focal distance and resolution required for conductivity, this work provides a reproducible starting point for producing low-cost, flexible, and biocompatible carbon electronics.

References

1. J. Lin et al., “Laser-induced porous graphene films from commercial polymers,” Nat. Commun. 5, 5714 (2014). DOI: 10.1038/ncomms6714
2. K. H. Chen et al., “Understanding Baseline Drift in Laser-Induced Graphene Electrodes and Its Impact on Heavy Metal Detection by Anodic Stripping Voltammetry,” J. Electroanal. Chem. (2026). PMID: 42182954
3. L. Huang & N. Zhao, “Laser-Induced Graphene-Polyimide Film Sensor for Simultaneous Lip Electromyography and Pressure Monitoring in Personalized Rehabilitation,” J. Vis. Exp. (2026). PMID: 42149837
4. L. Yang et al., “Thermoelectric porous laser-induced graphene-based strain-temperature decoupling and self-powered sensing,” Nat. Commun. 16, 1–12 (2025).
5. “Flash healing of laser-induced graphene,” Nat. Commun. 15, 1–11 (2024).
6. Y. Lu et al., “Universal modulus-free transfer of scalable laser-induced graphene for electronic skins,” Nat. Commun. 17, 1–12 (2026).