I. Abstract of the Paper’s Core Research

• Top-tier radiation resistance

It exhibits tolerance to a total ionizing dose of 4 Mrad at a high dose rate of 560 rad/s, and can withstand up to 15 Mrad in a low dose‑rate environment of 66.7 rad/s. Its performance degradation is significantly lower than that of commercial SOI silicon chips, with inverter voltage gain and conversion voltage drift kept within 25% and 15%, respectively.

• Damage can be repaired at low temperatures.

Ionogels exhibit liquid-like, reversible ion mobility. After exposure to high-dose radiation, a 10-minute low-temperature annealing at 100°C is sufficient to eliminate interface trap charges, fully restoring the electrical performance of transistors and inverters; moreover, the devices maintain stable operation even after multiple irradiation–annealing cycles.

• All-aerosol-printed active layer

Aerosol jetting enables the digital fabrication of carbon nanotube thin films, with precise control over network density. By employing an alumina buffer layer to tune device polarity, both P‑type and N‑type carbon nanotube transistors can be simultaneously fabricated, allowing the construction of a CMOS‑like logic inverter.

• Enhanced by a flexible, lightweight substrate

Replacing the silicon substrate with a thin polyimide film reduces scattering and reflection of high-energy particles, significantly decreasing substrate‑induced interface defects; after irradiation, the gate leakage current is two orders of magnitude lower than that of devices on a silicon substrate.

• Dual repair options available

In addition to thermal annealing for repair, heavily damaged devices can be refurbished by dissolving aged ionogels with a solvent and re‑printing the gate electrode via aerosol deposition, enabling the devices to be repeatedly regenerated and reused.

II. Core Technological Advantages of Aerosol Jet Printing for Electronics

Aerosol Spray Workflow

• A high-purity semiconductor carbon nanotube dispersion is introduced into the atomization chamber, where ultrasonic treatment generates uniform micron-sized aerosol droplets.
• Dual focusing by nitrogen carrier gas and coaxial sheath gas enables contactless, directional delivery to the polyimide substrate.
• The three-axis motion platform deposits carbon nanotube channels layer by layer along a CAD-defined path, enabling precise control over film density and channel dimensions.
• After printing, the substrate is dried at low temperature, followed by spin coating or aerosol deposition to fabricate the ionic‑gel gate, thereby completing the fabrication of the transistor array.

Five Unique Process Advantages (Compared to Lithography / Inkjet / Vapor Deposition)

• Flexible custom-shaped substrate adaptation

Non-contact deposition avoids scratching delicate, ultra-thin PI films; it enables stable printing on curved surfaces and ultra-thin flexible substrates, whereas silicon-based lithography is limited to rigid wafers.

• Carbon nanotube films are uniform and controllable, with high device consistency.

It enables precise control of the number of printing cycles to tune the density of the carbon nanotube network, allowing for the batch fabrication of transistors with extremely low threshold‑voltage dispersion and minimal performance variation after irradiation.

• Maskless digital manufacturing, streamlining the production line.

No metal photomask is required; circuit patterns are directly fabricated by computer, enabling rapid prototyping of small‑batch, specialized aerospace chips and significantly reducing R&D costs.

• Compatible with wide-viscosity inks, multi-layer integrated printing.

Carbon nanotube ink, conductive silver paste, and ionic gel precursor solutions can all be deposited via atomization using the same equipment, enabling one-step fabrication of the active layer and gate electrode.

• Low consumable usage, large-area continuous fabrication

Directional droplet deposition achieves a carbon nanotube feedstock utilization rate far exceeding that of spin coating; it is compatible with roll-to-roll production lines, meeting the demands of high-volume manufacturing for aerospace components.

III. Key Technological Innovations of This Study

Innovation 1: Co-Design of a Triple Radiation-Resistant Material Architecture

• Carbon nanotube channel: low atomic number and stable covalent bonds, making it resistant to knock-on damage under high-energy particle irradiation.
• Ionogel gate: a nanoscale double-layer equivalent gate dielectric, where radiation‑induced trapped charges can tunnel out; the ionic liquid itself withstands irradiation up to 40 Mrad.
• PI flexible thin substrate: reduces gamma-ray reflection and prevents the formation of Pb defect centers in silicon substrates, thereby suppressing irradiation‑induced leakage current at its source.
• A three-layer material architecture achieves an ultra‑high radiation tolerance that silicon chips cannot match.

Innovation 2: Precise modulation of carbon nanotube polarity via aerosol engineering, enabling the construction of complementary CMOS circuits.

Innovation 3: A reversible repair mechanism based on ionic gels, paving the way for irradiation‑reconfigurable chips.

Innovation 4: Aerosol-Based Digital Forming of Flexible, Large-Area Irradiated Integrated Circuits

Innovation 5: Dual Repair Process System

IV. Existing Process Challenges and Corresponding Solutions for Overcoming Them

Challenge 1: The conventional silicon substrate exhibits strong reflection of high-energy radiation, leading to a large number of interface traps.

Challenge 2: Native unipolar carbon nanotube devices are difficult to integrate into complementary logic circuits.

Challenge 3: Irradiation generates fixed-trap charges, leading to permanent failure of silicon-based chips.

Challenge 4: Lithography processes are complex, and flexible substrates are difficult to integrate with microfabrication.

Challenge 5: Ionic gels exhibit limited thermal stability at high temperatures, resulting in a narrow operational window for devices.

V. Future Diverse Real-World Application Scenarios

1. Deep Space Aerospace Electronic System

2. Nuclear Industry Measurement and Control Electronics

3. Polar / Deep-Sea Extreme Environment Exploration Equipment

4. Wearable Flexible Space Electronics

5. Lightweight Special-Purpose Military Electronics

Figure 1. Radiation‑resistant field-effect transistor (FET). a) Schematic illustrating a radiation‑resistant carbon nanotube (CNT) FET fabricated on a polyimide substrate using printed ionic gel; b) Scanning electron microscope (SEM) image showing a solution‑derived CNT thin film printed onto the polyimide substrate; inset: optical image of a CNT FET with finger‑like structures and an ionic gel layer serving as the dielectric; c) Transfer characteristics of a radiation‑hardened ionic‑gel‑based CNT FET before and after irradiation.

Figure 2. TID‑dependent evolution of the characteristics of ion‑gel carbon nanotube field‑effect transistors (CNT FETs) and CMOS‑like inverters fabricated on a silicon substrate. a. Transfer characteristics of ion‑gel CNT FETs on a silicon substrate under Vds = 0.25 V for various TID values; b. Variation of the Ion⁺/Ion⁻ ratio (where Ion⁺ and Ion⁻ denote the on‑currents of the n‑channel and p‑channel paths, respectively) and Vmin (the gate voltage at which Ids reaches its minimum) with TID; c. VTC curves of a CMOS‑like inverter under different TID conditions at Vdd = 1 V; d. Dependence of the peak gain and the switching threshold voltage of the CMOS‑like inverter on TID at Vdd = 1 V; e. VTC curves of the CMOS‑like inverter at Vdd = 1 V before and after irradiation with a low radiation dose rate; f. Voltage gain of the inverter as a function of Vin at Vdd = 1 V, before and after irradiation with a low radiation dose rate.

Figure 3. TID‑dependent evolution of the characteristics of ion‑gel carbon nanotube field‑effect transistors (CNT FETs) and CMOS‑like inverters fabricated on a polyimide substrate. a, Schematic illustrating lead elements on a silicon substrate and radiation‑induced interface defects; b, Schematic of a radiation‑hardened carbon nanotube FET after exposure to Co‑60 γ‑ray irradiation; c, Transfer characteristics of ion‑gel CNT FETs on a polyimide substrate at Vds = 0.25 V under various TID levels; d, Drain current versus TID for ion‑gel CNT FETs on different substrates at Vds = 0.25 V and Vgs = 1 V; e, Statistical distribution of drain currents for six FETs each on polyimide and silicon substrates, subjected to 4 Mrad irradiation at Vds = 0.25 V and Vgs = 1 V; f, Photograph of printed ion‑gel CNT FETs on a polyimide substrate; g, Output transfer characteristics (VTC) of a CMOS‑like inverter on a polyimide substrate at Vdd = 3 V for different TID values; h, Relationship between the minimum drain current voltage (corresponding to the Vgs value yielding the lowest Ids) of ion‑gel CNT FETs and the switching threshold voltage of the CMOS‑like ion‑gel CNT inverter at Vdd = 3 V as a function of TID.

Figure 4. Radiation‑induced damage repair in ionogel carbon nanotube field-effect transistors (CNT FETs) and CMOS‑like inverters achieved through moderate‑temperature annealing. a, Schematic illustrating the heat‑induced radiation‑repair process in the ionogel; b, Recovery of the voltage‑threshold characteristics of the heat‑induced CMOS‑like inverter; c, Performance of the ionogel CNT FET after multiple irradiation–repair cycles; d, Performance of the ionogel CMOS‑like inverter after multiple irradiation–repair cycles; e, Comparison of the performance of the ionogel CNT FETs and inverters subjected to radiation‑hardening treatments, prepared in this study and in previous work.

Table 1. Comparison of Radiation Characteristics of Various Published Integrated Circuits