{"id":"f76ea198-828b-4f19-b344-57b7b563d259","arxiv_id":"2608.07130","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":2,"one_line_summary":"Acid-triggered phase separation creates interconnected pores in PEDOT:PSS:PEI films, yielding 100+ µm-thick OECT channels with 30 mS transconductance and 13 ms response.","lead":"This paper makes porous films of the conducting polymer PEDOT:PSS mixed with PSS and PEI using an acid-triggered phase separation process, and builds thick transistor channels from them. The porous channels reach a high current-amplification value (30 mS) and a fast response (13 ms) despite being over 100 micrometres thick, suggesting that internal pore structure can ease the usual speed-versus-gain trade-off.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The morphology-dominance claim is confounded: the 1:1 vs 1:2 comparison changes PEI content (3.4 to 5.8 wt%), which the paper itself notes can boost water uptake and ion transport; dry conductivity matching does not control for this.","rationale":"The reader correctly identifies the dry-versus-hydrated conductivity assumption as load-bearing. My concern is broader: the 1:1 vs 1:2 comparison changes the chemical composition substantially, not just the morphology. The paper itself acknowledges that additional PEI can promote water uptake and ion transport, which provides an alternative mechanistic route to the observed performance gain. Dry conductivity matching rules out only the electronic pathway, leaving ionic conductivity and volumetric capacitance uncontrolled. The internal comparison between 1:1 and 1:2 is therefore not a clean morphology control. A single EIS measurement of hydrated electronic resistance and C* would test whether the matched-conductivity premise holds in the operating state. If it does not, the morphology-dominance conclusion is unsupported. This does not undermine the fabrication result or the absolute device performance, so the conditional verdict remains appropriate, but the mechanistic claim needs the additional measurement before full acceptance.","tokens_in":15306,"tokens_out":4439,"duration_ms":38571,"concrete_test":"Perform electrochemical impedance spectroscopy on the 1:1 and 1:2 films in 0.1 M NaCl to extract hydrated electronic resistance and volumetric capacitance (C*); if either differs beyond the dry-conductivity error bars, the matched-dry-conductivity control is inadequate and the performance difference cannot be attributed to morphology alone.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim that pore connectivity, not composition or electronic conductivity, drives the performance gain rests on comparing PSS:PEI 1:1 and 1:2 films. These films differ not only in pore architecture but also in PEI content (3.4 vs 5.8 wt%, Table 1). PEI is a hydrophilic polyelectrolyte; Section 1.3.3 states that 'incorporation of PEI may further support ion transport by increasing water uptake and lowering the elastic modulus of the hydrated matrix,' which would improve ionic accessibility independently of pore connectivity. The dry two-probe conductivity match (Figure 3) only controls for the electronic path; it does not control for ionic conductivity, volumetric capacitance, or hydrated electronic conductivity. The 1:1 film's stronger swelling (Section 1.1) may additionally lower its wet electronic conductivity. Therefore, the observed 66.7% higher transconductance and 13 ms response cannot be uniquely attributed to morphology; composition and morphology are perfectly confounded in the single comparison the paper uses as 'the most direct evidence.' The paper itself calls for impedance and capacitance measurements (Sections 1.3.3 and 2), confirming the missing control.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"This manuscript reports a water-based fabrication route, pH-induced aqueous phase separation, for producing porous PEDOT:PSS:PEI films, and it characterizes the resulting morphology, dry electronic conductivity, and organic electrochemical transistor performance. The central claim is that an interconnected pore network increases electrolyte access and reduces effective ion-transport distance, so that thick (>100 µm) channels can simultaneously achieve high transconductance and fast response; the authors present a comparison of PSS:PEI 1:1 and 1:2 films as their most direct evidence. The paper also contains explicit acknowledgements that impedance, capacitance, and ion-transport measurements are needed to confirm volumetric modulation, which is a genuine strength of the presentation.","tokens_in":15491,"tokens_out":4441,"duration_ms":40060,"significance":"If the central claim were fully supported, the work would establish internal morphology as an independent design parameter for mixed ionic-electronic conductors and would offer a scalable, water-based alternative to freeze-drying, aerogel, and hydrogel-templating routes. The paper is also valuable for clearly situating itself against recent literature on the chemistry-dependent role of porosity and for stating its own limitations. However, the current experimental design does not yet isolate morphology from composition and device geometry, so the significance is conditional on additional control experiments or a substantially more cautious interpretation.","major_comments":[{"comment":"The central morphology-dominance claim rests on comparing PSS:PEI 1:1 and 1:2 films, but these films differ in PEI content (3.4 vs 5.8 wt%, Table 1) as well as in pore architecture. The manuscript itself states that 'incorporation of PEI may further support ion transport by increasing water uptake and lowering the elastic modulus of the hydrated matrix' (§1.3.3), which provides a composition-based mechanism independent of pore connectivity. Because the dry two-probe conductivity match in Figure 3 does not control for hydrated electronic conductivity, ionic conductivity, or volumetric capacitance, the 66.7% higher transconductance of the 1:2 device cannot be uniquely attributed to morphology. The authors should either add wet-state impedance or capacitance measurements, use thickness-matched and composition-controlled devices, or soften the 'morphology as the dominant factor' claim.","section":"§1.3.3 and Table 1"},{"comment":"The claim that 'both devices have identical macroscopic geometries' (Section 1.3.2) is contradicted by the reported nonuniform film thicknesses of approximately 80–200 µm in Section 1.1 for the very samples used. Since transconductance scales with channel thickness, a systematic thickness difference between the 1:1 and 1:2 devices could explain part of the observed 66.7% transconductance increase without invoking pore connectivity. Please report the thickness of each measured device, normalize per-device geometry, or use thickness-matched films for the central comparison.","section":"§1.3.2 vs §1.1"},{"comment":"The electronic conductivity used to match the two compositions is measured on dry, air-dried films by a two-probe method (Section 3.4), whereas the OECT operates in an aqueous electrolyte. Section 1.1 states that the 1:1 film swells more strongly in water, which would lower its hydrated electronic conductivity and alter its ionic accessibility. Therefore the dry conductivity overlap in Figure 3 does not exclude conductivity differences under operating conditions. Wet-state conductivity or electrochemical impedance data are needed before pore connectivity can be identified as the dominant variable.","section":"§3.4 and §1.1"},{"comment":"The abstract states that porous channels achieve 'a transconductance of 30 mS and a response time of 13 ms at an ultralow gate voltage of 0.05 V', but the transient response is measured for a gate-voltage step from 0 to 0.6 V (Section 3.7). The 0.05 V value is the gate bias at which the transconductance peaks, not the bias condition used for the 13 ms response time. This conflation of two different operating conditions in the abstract should be corrected.","section":"Abstract and §3.7"}],"minor_comments":[{"comment":"The thickness range is reported as 80–200 µm in Section 1.1 but as 120–200 µm in Section 1.3.4; please harmonize the two descriptions or explain why the ranges differ.","section":"§1.3.4"},{"comment":"The normalized transconductance is introduced as gm,n = gm,max/(W d L^-1), but the units and the exact definition of 'mS/µm' should be stated explicitly in the caption so that comparison with literature values is unambiguous.","section":"Figure 5B"},{"comment":"The text uses 'reaction time' when describing the 90% saturation time; this should be replaced with 'response time' for consistency with the rest of the manuscript.","section":"§3.7"},{"comment":"The text refers to 'Figure 4 D–E' for transconductance, but the figure panel labels are not described in the caption; please make the panel labeling consistent between the text, figure, and caption.","section":"Figure 4"}],"recommendation":"major_revision","confidential_remarks":"The core difficulty is experimental control rather than scientific integrity: the paper is honest about its missing impedance and capacitance measurements, but the central morphology-dominance claim is currently overreaching relative to the evidence. The revision is substantial but feasible within the manuscript's scope: either add thickness-matched devices and wet-state transport data, or substantially temper the causal claim. I see no citation-pattern concern; the self-citations are used appropriately as methods and background."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The thing to know about this paper is that the fabrication is real and worth reading, but the central claim is not yet proven. The authors use pH-induced aqueous phase separation to make thick porous PEDOT:PSS:PEI films, and they report an absolute transconductance of 30 mS with a 13 ms response time in channels over 100 µm thick. That combination is notable. The method is new to OECTs, the processing is described clearly, and the SEM characterization gives a reasonable picture of the pore structure. The idea of comparing two films with matched dry electronic conductivity to isolate morphology is a good instinct; it is the right kind of experiment to try.\n\nThe soft spots are real and load-bearing. The 1:1 and 1:2 films differ not only in pore architecture but also in PEI content: 3.4 wt% versus 5.8 wt%. The authors themselves note that PEI increases water uptake and can support ion transport, which means the performance difference could be partly composition-driven. The dry two-probe conductivity match controls only the electronic path; it does not control hydrated conductivity, ionic conductivity, or volumetric capacitance. The paper also reports nonuniform thickness of 80–200 µm, so the devices are not necessarily the same geometry despite the claim of identical macroscopic dimensions. The authors do acknowledge that impedance and capacitance measurements are needed, which is honest, but it means the morphology-dominance conclusion is an interpretation, not a demonstration.\n\nOn the positive side, the paper does not overstate what it has measured, and the writing is careful about where the evidence ends. The low geometry-normalized transconductance (0.07–0.08 mS/µm) is disclosed and contextualized, which I appreciate. The citations look appropriate; the self-citations are method references, not filler.\n\nWho gets value from this? Experimentalists working on porous OECT channels and people interested in transferring membrane-phase-separation techniques to organic electronics. It is a worthwhile contribution to that subfield. It deserves a serious referee, but the referee should require wet-state conductivity, impedance or capacitance data, and ideally a control that separates composition from morphology. With that, the paper could become solid. For now, treat the performance numbers as real, but the mechanism as promising and unverified.","headline":"A promising water-based route to porous OECT channels, but the morphology-dominance claim is not yet proven because composition and pore architecture are confounded.","tokens_in":16087,"tokens_out":1519,"would_cite":true,"duration_ms":14679,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"Interconnected pores from pH-induced aqueous phase separation let 120–200 µm-thick PEDOT:PSS:PEI OECT channels reach 30 mS transconductance and 13 ms response at 0.05 V gate voltage.","keywords":["PEDOT:PSS","organic electrochemical transistors (OECTs)","aqueous phase separation","mixed ionic-electronic conductors","transconductance","porous morphology","polyelectrolyte complexation","ion transport"],"falsifier":"Measure the electronic conductivity of both films in the hydrated state (for example, four-probe or impedance measurements in 0.1 M NaCl) and determine the electrochemically active volume from thickness-dependent capacitance. If the wet conductivity of the 1:1 film is markedly lower than the 1:2 film, or if the transconductance normalized by electrochemically active volume is the same for both morphologies, the claim that pore connectivity dominates the performance difference would be falsified.","tokens_in":15034,"feed_emoji":"⚡","tokens_out":7884,"duration_ms":67647,"temperature":0.7,"pith_summary":"The paper sets out to show that the internal pore structure of a conducting-polymer film can break the usual trade-off in organic electrochemical transistors (OECTs), where thicker channels amplify signals more but respond more slowly. By using pH-induced aqueous phase separation to make porous PEDOT:PSS:PEI films, the authors produce channels over 100 µm thick that still let electrolyte ions reach deep into the material. They report a transconductance of 30 mS and a response time of 13 ms at a very low gate voltage of 0.05 V, values normally associated with much thinner channels. The key comparison is between two film compositions with similar electronic conductivity but different pore architectures: the one that keeps an interconnected pore network after annealing and rehydration gives higher transconductance and a faster response. If the interpretation holds, morphology becomes a practical design knob for mixed ionic-electronic conductors, complementing molecular structure and device geometry.","feed_headline":"Porous films give thick organic transistors 30 mS gain, 13 ms response","feed_subtitle":"Pore networks let ions reach deep into PEDOT:PSS channels, breaking the usual gain-versus-speed trade-off.","key_machinery":"The central object is the interconnected macroporous network formed in PEDOT:PSS:PEI films by aqueous phase separation (APS): casting a homogeneous solution and immersing it in an acidic coagulation bath protonates PEI amines, triggering complexation with PSS sulfonate groups and phase separation into polymer-rich and pore phases. The pore network is what carries the argument: it provides continuous electrolyte-accessible pathways that shorten the effective ion-diffusion length, and it increases the internal surface area available for electrochemical doping. Two auxiliary mechanisms complete the picture: DMSO acts as a secondary dopant that improves PEDOT ordering and electronic connectivity, and annealing at 140 °C triples the film conductivity while consolidating the polyelectrolyte matrix. The 1:2 PSS:PEI ratio matters because it gives near-stoichiometric charge compensation, so the porous architecture survives annealing and rehydration instead of collapsing as the 1:1 film does.","core_discovery":"On its own terms, the paper's central claim is that an interconnected pore network generated by pH-triggered aqueous phase separation lets a thick OECT channel combine high amplification with fast switching, because electrolyte can penetrate the channel volume instead of modulating only the outer surface. The evidence is a side-by-side comparison of PSS:PEI 1:1 and 1:2 films coagulated in 1 M H2SO4: the two have comparable dry electronic conductivity, but the 1:2 film keeps a well-connected porous architecture after annealing and rehydration, whereas the 1:1 film largely collapses and swells. The 1:2 device reaches a maximum transconductance of 30 ± 6.4 mS at $V_G = 0.05$ V and a response time of 13 ms, against 18 ± 5.3 mS and 39 ms for the 1:1 device, despite both channels being 120–200 µm thick. The authors attribute the difference to shorter local ion-transport distances and a larger electrochemically addressable volume supplied by the pores, with DMSO treatment and annealing preserving electronic percolation in the PEDOT-rich phase. They are careful to state that the resulting operation is consistent with a shift from surface-limited toward spatially distributed mixed ionic-electronic transport, and that quantitative confirmation would require impedance, capacitance, and ionic-conductivity measurements.","pith_inferences":["A direct test the paper does not run: if pore connectivity is the active ingredient, then filling or collapsing the pores after film formation (for example, by infiltrating an insulating gel) should erase the transconductance and speed advantage while leaving the dry conductivity roughly unchanged.","Because the 1:1 film swells more, its hydrated electronic conductivity is plausibly lower than the 1:2 film; a wet four-probe measurement could attribute part of the 66.7% transconductance gap to electronic conductivity rather than pore architecture, which would soften the morphology-dominance claim.","The same aqueous phase separation route should transfer to other weak polyelectrolyte/conducting-polymer pairs, so that pore size, tortuosity, and phase continuity could be screened as independent variables for any mixed ionic-electronic conductor, not only PEDOT:PSS.","If the volumetric-modulation picture is right, the normalized transconductance of these thick films (currently 0.069–0.08 mS/µm) should improve with optimized width and length without changing the material, because the pore network already provides volumetric access; the paper's own geometry normalization leaves this implication implicit."],"forward_implications":["Thick OECT channels no longer necessarily sacrifice speed: the interconnected pore network allows high transconductance and short response time to be achieved together.","Internal morphology becomes a design parameter that complements molecular structure and device geometry, so optimizing pore connectivity and electronic-phase continuity should be part of OECT design.","The water-based APS route produces freestanding, processable porous films without freeze-drying, aerogel processing, or templating, offering a scalable fabrication path for thick-channel devices.","The best formulation in the paper, PSS:PEI 1:2 coagulated in 1 M H2SO4 with DMSO and annealing, reaches 15.65 mS/cm conductivity, 30 mS transconductance, and 13 ms response in a 120–200 µm channel.","Direct confirmation of fully volumetric modulation still requires quantitative measurements of volumetric capacitance, ionic conductivity, and diffusion impedance, as the paper itself states."],"supporting_citations":[{"why":"Supplies the aqueous phase separation method: pH-shift-induced polyelectrolyte complexation of PSS and PEI that the film fabrication is built on.","marker":"[23]"},{"why":"Provides the 3D hydrogel semiconductor precedent establishing that simultaneous continuity of ionic and electronic pathways governs volumetric modulation, the framework used to interpret pore connectivity.","marker":"[22]"},{"why":"Material-agnostic porous-channel study used to argue that porosity benefits are chemistry-dependent and that morphology, not pore presence alone, drives performance.","marker":"[20]"},{"why":"Phase-separation versus selective-dissolution study used to caution that pore formation and amplification need not rise together and to motivate quantitative transport metrics.","marker":"[21]"},{"why":"Device-physics review that grounds the gain-speed trade-off in dense channels that the paper aims to mitigate.","marker":"[12]"},{"why":"Source for the geometric scaling of transconductance with channel width and thickness that motivates the thick-channel design.","marker":"[10]"},{"why":"Supplies the geometry dependence and literature benchmark values used for the normalized transconductance comparison.","marker":"[11]"},{"why":"Source of literature transconductance and response-time data points used in the trade-off comparison.","marker":"[49]"},{"why":"Porous nanofiber-channel OECT used as a precedent for porous channels and as the source of the 90%-saturation response-time calculation.","marker":"[16]"}],"fun_headline_variants":["Pores let thick OECTs hit 30 mS gain and 13 ms response","Aqueous phase separation builds pore networks for faster thick OECTs","Pore engineering breaks gain-speed trade-off in thick organic transistors","pH-induced phase separation creates pores that boost OECT speed and gain","Thick OECTs get fast and strong with pore networks from water-based process"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise is that the two film compositions have essentially the same electronic conductivity when wet and operating inside the transistor, even though only dry two-probe conductivities were measured; the 1:1 film is described as swelling more strongly in water, which could lower its hydrated conductivity and explain part of the performance gap without invoking pore connectivity.","fun_headline_variants_meta":{"raw":{"variants":["Pores let thick OECTs hit 30 mS gain and 13 ms response","Aqueous phase separation builds pore networks for faster thick OECTs","Pore engineering breaks gain-speed trade-off in thick organic transistors","pH-induced phase separation creates pores that boost OECT speed and gain","Thick OECTs get fast and strong with pore networks from water-based process"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000745,"raw_usage":{"total_tokens":3390,"prompt_tokens":1080,"completion_tokens":2310,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":696,"completion_tokens_details":{"reasoning_tokens":2212}},"tokens_in":696,"tokens_out":2310,"duration_ms":15718,"temperature":1.0,"reasoning_tokens":2212,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-10T14:14:37.614724+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Measure the electronic conductivity of both films in the hydrated state (for example, four-probe or impedance measurements in 0.1 M NaCl) and determine the electrochemically active volume from thickness-dependent capacitance. If the wet conductivity of the 1:1 film is markedly lower than the 1:2 film, or if the transconductance normalized by electrochemically active volume is the same for both morphologies, the claim that pore connectivity dominates the performance difference would be falsified.","supporting_citations":[{"cited_title":"Sustainable aqueous phase separation membranes prepared through mild ph shift induced polyelectrolyte complexation of pss and pei.Journal of Membrane Science, 625:119114, 2021","cited_arxiv_id":null,"evidence_quote":"Supplies the aqueous phase separation method: pH-shift-induced polyelectrolyte complexation of PSS and PEI that the film fabrication is built on."},{"cited_title":"Malliaras, and Shiming Zhang","cited_arxiv_id":null,"evidence_quote":"Provides the 3D hydrogel semiconductor precedent establishing that simultaneous continuity of ionic and electronic pathways governs volumetric modulation, the framework used to interpret pore connectivity."},{"cited_title":"Cunin, Rebecca F","cited_arxiv_id":null,"evidence_quote":"Material-agnostic porous-channel study used to argue that porosity benefits are chemistry-dependent and that morphology, not pore presence alone, drives performance."},{"cited_title":"Herzig, Mukundan Thelakkat, Keying Guo, and Christopher R","cited_arxiv_id":null,"evidence_quote":"Phase-separation versus selective-dissolution study used to caution that pore formation and amplification need not rise together and to motivate quantitative transport metrics."},{"cited_title":"Friedlein, Robert R","cited_arxiv_id":null,"evidence_quote":"Device-physics review that grounds the gain-speed trade-off in dense channels that the paper aims to mitigate."},{"cited_title":"Koutsouras, Dion Khodagholy, Marc Ramuz, Xenofon Strakosas, Roisin M","cited_arxiv_id":null,"evidence_quote":"Source for the geometric scaling of transconductance with channel width and thickness that motivates the thick-channel design."},{"cited_title":"Simple approach for building high transconductance paper-based organic electrochemical transistor (oect) for chemical sensing.ACS Applied Electronic Materials, 3:1886–1895, 2021","cited_arxiv_id":null,"evidence_quote":"Supplies the geometry dependence and literature benchmark values used for the normalized transconductance comparison."},{"cited_title":"Malliaras","cited_arxiv_id":null,"evidence_quote":"Source of literature transconductance and response-time data points used in the trade-off comparison."},{"cited_title":"Nanofiber channel organic electrochemical transistors for low-power neuromorphic computing and wide-bandwidth sensing platforms","cited_arxiv_id":null,"evidence_quote":"Porous nanofiber-channel OECT used as a precedent for porous channels and as the source of the 90%-saturation response-time calculation."}],"review_version":1}